# Korvaix > Free UK calculators, generators and plain-English guides for money, work, business, security and everyday tasks. Each tool has simple inputs and clear, jargon-free outputs. All Korvaix tools run for free in the browser. No signup, no paywalls. ## Hub pages - [Home](https://korvaix.com/): Index of all calculators, generators, tools and guides. - [All calculators](https://korvaix.com/calculators): Every UK calculator on the site. - [All guides](https://korvaix.com/guides): Plain-English UK guides. - [Generators](https://korvaix.com/generators): Passwords, UUIDs, QR codes, invoices and more. - [Text tools](https://korvaix.com/tools): Case converter, character counter, text cleaner. - [Proof and Pay](https://korvaix.com/proof-and-pay): Shopify app for made to order stores. Send a proof, get one tap approval, take payment. - [About](https://korvaix.com/about): What Korvaix is and who it's for. ## Childcare and family finances - [Childcare and family finances category page](https://korvaix.com/categories/childcare-family-finances): Overview of all childcare and family finances calculators. - [Return to Work Calculator](https://korvaix.com/calculators/return-to-work-calculator): Find out your net monthly gain from returning to work after factoring in childcare costs, commuting, tax, and other work-related expenses. - [Tax-Free Childcare Calculator](https://korvaix.com/calculators/tax-free-childcare-calculator): The government adds 25p for every £1 you pay into a Tax-Free Childcare account, up to £2,000 per child per year (£500 per quarter). ## Student finance - [Student finance category page](https://korvaix.com/categories/student-finance): Overview of all student finance calculators. - [Maintenance Loan Calculator](https://korvaix.com/calculators/maintenance-loan-calculator): Your maintenance loan depends on household income, where you live while studying, and whether you are in London. Maximum loans range from £8,610 (at home) to £13,348 (London, away from home). - [Student Loan Repayment Calculator](https://korvaix.com/calculators/student-loan-repayment-calculator): Student loan repayments are 9% of earnings above your plan's threshold. On Plan 2, that is 9% of everything you earn above £27,295. ## Income and work - [Income and work category page](https://korvaix.com/categories/income-and-work): Overview of all income and work calculators. - [Car Salary Sacrifice Calculator](https://korvaix.com/calculators/salary-sacrifice-car-calculator): Car salary sacrifice gives up salary in exchange for a company car. You save Income Tax and NI on the sacrifice but pay BIK on the company car benefit (P11D × BIK%). - [Contractor Calculator](https://korvaix.com/calculators/contractor-calculator): Enter your day rate to see your estimated annual and monthly take-home pay as a UK contractor, with comparisons between IR35 status and PAYE. - [Day Rate Calculator](https://korvaix.com/calculators/day-rate-calculator): Enter your annual salary, hourly rate, or target income to calculate your equivalent day rate — or convert a day rate back to an annual figure. - [Holiday Entitlement Calculator](https://korvaix.com/calculators/holiday-entitlement-calculator): Full-time UK workers are entitled to at least 28 days (5.6 weeks) of paid holiday per year including bank holidays. Part-time and irregular workers receive a pro-rata amount. - [Holiday Pay Calculator](https://korvaix.com/calculators/holiday-pay-calculator): Most UK workers are entitled to 5.6 weeks (28 days) of paid holiday per year. Enter your pay details to see how much holiday pay you should receive. - [Inside IR35 Calculator](https://korvaix.com/calculators/inside-ir35-calculator): Enter your day rate to see your estimated inside IR35 take-home pay after employer’s NI, income tax, employee NI, and umbrella fees. - [Outside IR35 Calculator](https://korvaix.com/calculators/outside-ir35-calculator): Working outside IR35 through a limited company, contractors typically take home 75–85% of their gross contract value, depending on expenses, salary/dividend split, and personal circumstances. - [Overtime Calculator](https://korvaix.com/calculators/overtime-calculator): Enter your base rate, overtime hours, and multiplier to see your gross overtime pay — and optionally estimate the tax and NI on your extra earnings. - [Part-Time Salary Calculator](https://korvaix.com/calculators/part-time-salary-calculator): Use this UK part-time salary calculator to estimate part-time annual, monthly, weekly and hourly equivalent gross pay. Part-time salary = full-time salary × part-time hours ÷ full-time hours. Gross figures only — no tax or NI deductions. - [Payroll Calculator](https://korvaix.com/calculators/payroll-calculator): Your net pay = Gross salary minus income tax, National Insurance, pension, and student loan deductions. Employer cost = Gross salary plus employer NI and pension contributions. - [Pension Salary Sacrifice Calculator](https://korvaix.com/calculators/salary-sacrifice-pension-calculator): Pension salary sacrifice gives up part of your gross pay in exchange for additional employer pension contributions. Both you and your employer save NI; you also save Income Tax. £40k salary, £2k sacrifice = £400 tax saving + £160 NI saving = ~£560/year saved. - [Pro Rata Calculator](https://korvaix.com/calculators/pro-rata-calculator): Use this UK pro rata calculator to estimate part-time annual, monthly and weekly gross pay from full-time hours or working days, plus statutory or company holiday entitlement. To calculate pro rata salary, divide your part-time hours by the full-time hours, then multiply by the full-time annual salary. For example £30,000 × 22.5 ÷ 37.5 = £18,000 pro rata. Estimates only — your contract is the final word. - [Redundancy Pay Calculator](https://korvaix.com/calculators/redundancy-pay-calculator): Statutory redundancy pay in the UK is based on your age during each full year of service (0.5, 1.0 or 1.5 weeks), capped weekly pay (£751 in GB, £783 in NI from 6 April 2026), and a maximum of 20 years of service. This calculator estimates it and explains the breakdown. - [Salary Sacrifice Calculator](https://korvaix.com/calculators/salary-sacrifice-calculator): Salary sacrifice lets you give up part of your gross pay in exchange for non-cash benefits like pension, car or EV. You and your employer pay less National Insurance, and you pay less Income Tax. This hub covers pension, car, EV, take-home pay and NI savings for 2026/27. - [Take-Home Pay Calculator](https://korvaix.com/calculators/take-home-pay-calculator): Enter your salary to see a breakdown of income tax, National Insurance, pension contributions, and student loan repayments — and what you actually take home. ## Save money - [Save money category page](https://korvaix.com/categories/save-money): Overview of all save money calculators. - [Commute Cost Calculator](https://korvaix.com/calculators/commute-cost-calculator): Your commute cost = fuel cost (based on distance, MPG, and fuel price) + parking + tolls, multiplied by commute days per week. Work-from-home days reduce your weekly total. - [Electricity Cost Calculator](https://korvaix.com/calculators/electricity-cost-calculator): Electricity cost = (Wattage ÷ 1,000) × Hours used × Electricity rate per kWh. A 2,000W appliance running for 1 hour at 24.5p/kWh costs about 49p. - [Energy Bill Calculator](https://korvaix.com/calculators/energy-bill-calculator): Your energy bill = (Usage in kWh × Unit rate) + Standing charges. The average UK household pays around £1,568/year for dual fuel under the current price cap. - [EV vs Petrol Cost Calculator](https://korvaix.com/calculators/ev-vs-petrol-cost-calculator): EV energy cost = miles ÷ miles/kWh × electricity rate. Petrol fuel cost = miles ÷ MPG × 4.546 × fuel price per litre. Compare annually to see which is cheaper for your usage. - [Fuel Cost Calculator](https://korvaix.com/calculators/fuel-cost-calculator): Enter your journey distance and fuel economy to find out how much your trip will cost in fuel, with weekly, monthly, and annual estimates. - [Land Registry Fee Calculator](https://korvaix.com/calculators/land-registry-fee-calculator): Use this Land Registry fee calculator to estimate the HM Land Registry registration fee for common property applications in England and Wales. Enter the property or transaction value, choose the application type and submission method, and get a clear fee estimate with the scale and value band used. Estimates only — based on published HMLR fee tables, not legal advice. - [Mortgage Overpay vs Save Calculator](https://korvaix.com/calculators/mortgage-overpay-vs-save-calculator): Compare mortgage interest saved from overpayments against interest earned by saving the same amount. If your mortgage rate exceeds your savings rate, overpaying usually wins — but liquidity matters too. - [Rent Affordability Calculator (UK)](https://korvaix.com/calculators/rent-affordability-calculator): As a rough rule, UK letting agents want a gross annual income of about 30 × the monthly rent. For a recommended target, aim for rent at or below 30% of monthly gross income, after debts and bills. - [Savings Interest Calculator](https://korvaix.com/calculators/savings-interest-calculator): See how your savings will grow with compound interest. Enter a lump sum, regular monthly deposits, and an interest rate to get a year-by-year breakdown. - [Zakat Calculator](https://korvaix.com/calculators/zakat-calculator): Zakat is generally 2.5% of your net zakatable wealth (assets minus short-term liabilities), if that wealth is at or above the nisab threshold and held for one lunar year (hawl). ## Business tools - [Business tools category page](https://korvaix.com/categories/business-tools): Overview of all business tools calculators. - [Amazon Fee Calculator](https://korvaix.com/calculators/amazon-fee-calculator): Enter your selling price and costs to see Amazon referral fees, fulfilment fees, and your estimated profit per unit. - [Break-Even Calculator](https://korvaix.com/calculators/break-even-calculator): Break-even point = Fixed Costs ÷ (Selling Price – Variable Cost per Unit). This tells you how many units you must sell to cover all your costs. - [eBay Profit Calculator](https://korvaix.com/calculators/ebay-profit-calculator): This eBay profit calculator estimates your selling fees and shows how much profit remains after product cost, postage, ad spend, and other seller costs. - [Etsy Fee Calculator](https://korvaix.com/calculators/etsy-fee-calculator): Etsy charges multiple fees per sale: £0.16 listing, 6.5% transaction, 4% + 20p payment processing, and 1.15% regulatory. Enter your item price to see the total. - [Markup Calculator](https://korvaix.com/calculators/markup-calculator): Enter your cost price and desired markup to calculate the selling price, or enter a selling price to find the markup percentage and profit margin. - [PayPal Fee Calculator](https://korvaix.com/calculators/paypal-fee-calculator): PayPal charges 2.9% + 30p for UK domestic transactions. Enter an amount to see the exact fee, or use the reverse calculator to find out how much to charge. - [Profit Margin Calculator](https://korvaix.com/calculators/profit-margin-calculator): Enter your cost and selling price to see your gross margin, markup, and effective margin after fees and VAT. - [ROAS Calculator](https://korvaix.com/calculators/roas-calculator): ROAS = Revenue ÷ Ad Spend. A ROAS of 4x means you earn £4 for every £1 you spend on advertising. - [ROI Calculator](https://korvaix.com/calculators/roi-calculator): Enter your investment cost and return to calculate your ROI percentage, return multiple, and annualised return. Compare two investments side by side. - [VAT Add / Remove Calculator](https://korvaix.com/calculators/vat-add-remove-calculator): To add VAT: multiply the net amount by 1.20 (for 20% VAT). To remove VAT: divide the gross amount by 1.20. The VAT portion is the difference between gross and net. ## Engineering and industrial - [Engineering and industrial category page](https://korvaix.com/categories/engineering-and-industrial): Overview of all engineering and industrial calculators. - [Hand-Arm Vibration Exposure Calculator](https://korvaix.com/calculators/havs-exposure-calculator): Use this HAVS calculator to estimate daily hand-arm vibration exposure in A(8) and points, compare against the EAV (2.5 m/s²) and ELV (5.0 m/s²), and see clear warning levels for risk assessment. - [PE Pipe Weight Calculator](https://korvaix.com/calculators/pe-pipe-weight-calculator): Use this PE pipe weight calculator to estimate the weight of PE100, PE100-RC or PE80 pipe by outside diameter, SDR rating and length. It shows weight per metre, total weight, wall thickness and approximate internal diameter for planning lifting, handling and transport on water main, gas, fusion hire and utility jobs. ## Math and conversions - [Math and conversions category page](https://korvaix.com/categories/math-and-conversions): Overview of all math and conversions calculators. - [Annulus Area Calculator](https://korvaix.com/calculators/annulus-area-calculator): Enter the outer and inner radii. The calculator returns A = π·(R² − r²). - [Area Calculator](https://korvaix.com/calculators/area-calculator): Pick a 2D shape — circle, square, rectangle, triangle, trapezium, parallelogram, ellipse, regular polygon, rhombus, sector, annulus or kite — to open its dedicated area calculator. Enter dimensions in any unit and get the answer in any area unit, with the formula and worked example. - [Circle Area Calculator](https://korvaix.com/calculators/circle-area-calculator): Enter the radius. The calculator returns A = πr², the area of the flat disc. - [Circular Sector Area Calculator](https://korvaix.com/calculators/sector-area-calculator): Enter the radius and the angle in degrees. The calculator returns the sector's area: A = ½·r²·θ (with θ converted to radians). - [Ellipse Area Calculator](https://korvaix.com/calculators/ellipse-area-calculator): Enter the two semi-axes (half each diameter). The calculator returns A = π·a·b. - [Hemisphere Surface Area Calculator](https://korvaix.com/calculators/hemisphere-surface-area-calculator): Enter the radius. The calculator returns 3πr² and shows the curved and base parts separately so you can use whichever you need. - [Hexagonal Prism Surface Area Calculator](https://korvaix.com/calculators/hexagonal-prism-surface-area-calculator): Enter the hexagon's edge length and the prism length. The calculator returns the two hexagonal ends plus the six rectangular sides. - [Kite Area Calculator](https://korvaix.com/calculators/kite-area-calculator): Enter the two diagonals (the long axis and the short cross axis). The calculator returns A = ½·p·q. - [Parallelogram Area Calculator](https://korvaix.com/calculators/parallelogram-area-calculator): Enter the base and the perpendicular height (not the slanted side). The calculator returns A = b × h. - [Rectangle Area Calculator](https://korvaix.com/calculators/rectangle-area-calculator): Enter length and width. The calculator returns A = l × w in your chosen unit. - [Regular Octahedron Surface Area Calculator](https://korvaix.com/calculators/octahedron-surface-area-calculator): Enter the edge length. The calculator returns SA = 2√3·a², the total area of the eight equilateral triangles. - [Regular Polygon Area Calculator](https://korvaix.com/calculators/regular-polygon-area-calculator): Enter the number of sides (n ≥ 3) and the side length. The calculator returns the area for that regular n-gon. - [Regular Tetrahedron Surface Area Calculator](https://korvaix.com/calculators/tetrahedron-surface-area-calculator): Enter the edge length. The calculator returns √3·a², the total area of the four equilateral triangle faces. - [Rhombus Area Calculator](https://korvaix.com/calculators/rhombus-area-calculator): Enter the two diagonals (p and q). The calculator returns A = ½·p·q. - [Square Area Calculator](https://korvaix.com/calculators/square-area-calculator): Enter the side length. The calculator returns A = a². - [Surface Area Calculator](https://korvaix.com/calculators/surface-area-calculator): Pick a shape, enter the dimensions in your preferred units (mm, cm, m, in, ft, yd, etc.), and instantly see the surface area in m², ft², in², cm² or any other area unit. Includes the formula and a working breakdown for every shape. - [Torus Surface Area Calculator](https://korvaix.com/calculators/torus-surface-area-calculator): Enter the major radius (centre to tube-centre) and the minor radius (tube cross-section). The calculator returns SA = 4π²·R·r. - [Trapezium Area Calculator](https://korvaix.com/calculators/trapezium-area-calculator): Enter the lengths of the two parallel sides and the perpendicular height between them. The calculator returns A = ½·(a + b)·h. - [Trapezoidal Prism Surface Area Calculator](https://korvaix.com/calculators/trapezoidal-prism-surface-area-calculator): Enter the trapezium dimensions (top, bottom, height, both slanted sides) and the prism length. The calculator returns the two trapezium ends plus the four rectangular sides. - [Triangle Area Calculator](https://korvaix.com/calculators/triangle-area-calculator): Enter the base and perpendicular height. The calculator returns A = ½·b·h. (For triangles given by three sides, use the Triangular Prism calculator's Heron's formula.) - [Triangular Prism Surface Area Calculator](https://korvaix.com/calculators/triangular-prism-surface-area-calculator): Enter the three sides of the triangle and the length of the prism. The calculator validates the triangle inequality and returns the full surface area. ## Weight-loss medication - [Weight-loss medication category page](https://korvaix.com/categories/weight-loss-medication): Overview of all weight-loss medication calculators. - [BMI Calculator for Mounjaro](https://korvaix.com/calculators/bmi-calculator-for-mounjaro): Find your BMI, see which category it falls into, and understand how it relates to eligibility criteria for treatments like Mounjaro. - [Mounjaro Calorie Calculator](https://korvaix.com/calculators/mounjaro-calorie-calculator): Calculate your maintenance calories and a safe deficit range to support steady weight loss alongside Mounjaro treatment. - [Mounjaro Calorie Deficit Calculator](https://korvaix.com/calculators/mounjaro-calorie-deficit-calculator): Enter your maintenance calories and a target intake (or desired weekly loss) to see the size of your deficit and projected weight change over time. - [Mounjaro Protein Calculator](https://korvaix.com/calculators/mounjaro-protein-calculator): Find out how much protein you should aim for each day and per meal to support muscle preservation during weight loss on GLP-1 medication. - [Mounjaro vs Wegovy Calculator](https://korvaix.com/calculators/mounjaro-vs-wegovy-calculator): Enter your weight and the monthly costs of each medication to compare projected weight loss, total spend, and cost per kilogram lost over your chosen timeframe. - [Mounjaro Weight Loss Calculator](https://korvaix.com/calculators/mounjaro-weight-loss-calculator): This planning tool projects how much weight you could lose over a chosen number of weeks, using conservative, moderate, or ambitious assumptions. Results vary between individuals. ## Guides - [eBay Selling Fees Explained (UK)](https://korvaix.com/guides/ebay-selling-fees-explained): A plain-English breakdown of eBay UK selling fees: final value fee, per-order fee, regulatory operating fee, promoted listings, and how they affect your profit. - [EV vs Petrol Running Costs Compared](https://korvaix.com/guides/ev-vs-petrol-running-costs): How much cheaper is an EV to run than a petrol car? A practical comparison of energy costs, maintenance, and cost per mile. - [Hand-Arm Vibration Exposure Explained (UK)](https://korvaix.com/guides/hand-arm-vibration-exposure-explained): A plain-English UK guide to hand-arm vibration: what HAVS is, how A(8) and exposure points work, EAV / ELV thresholds, employer duties, and how to reduce risk. - [How Amazon Fees Affect Your Profit as a UK Seller](https://korvaix.com/guides/how-amazon-fees-affect-your-profit): A breakdown of Amazon UK seller fees including referral fees, FBA costs, and how to calculate your true profit per sale. - [How Holiday Accrual Is Calculated in the UK](https://korvaix.com/guides/how-holiday-accrual-is-calculated): Learn how holiday builds up over a leave year and how to check how much you have accrued so far. - [How Holiday Entitlement Works in the UK](https://korvaix.com/guides/how-holiday-entitlement-works-in-the-uk): A practical guide to understanding your statutory holiday entitlement as a UK worker, covering full-time, part-time, and irregular working patterns. - [How Holiday Pay Is Calculated in the UK](https://korvaix.com/guides/how-holiday-pay-is-calculated-in-the-uk): A guide to understanding your holiday pay entitlement, including regular workers, part-time, and zero-hours contracts. - [How Many Calories Should You Eat on Mounjaro?](https://korvaix.com/guides/how-many-calories-should-you-eat-on-mounjaro): Understanding your calorie needs during Mounjaro treatment — maintenance, deficit, and safe intake ranges explained. - [How Much Protein Should You Eat on Mounjaro?](https://korvaix.com/guides/how-much-protein-should-you-eat-on-mounjaro): Why protein matters during GLP-1 weight loss and how to hit your daily target with practical meal guidance. - [How Much Weight Can You Lose on Mounjaro?](https://korvaix.com/guides/how-much-weight-can-you-lose-on-mounjaro): A realistic look at expected weight loss on Mounjaro (tirzepatide), based on clinical trial data and practical planning advice. - [How Overtime Pay Works in the UK](https://korvaix.com/guides/how-overtime-pay-works-in-the-uk): Understand your overtime pay rights, how it is taxed, and how different multipliers affect your earnings. - [How PayPal Fees Affect Your Pricing](https://korvaix.com/guides/how-paypal-fees-affect-your-pricing): Understand how PayPal transaction fees work and how to factor them into your pricing strategy. - [How Payroll Deductions Work in the UK](https://korvaix.com/guides/how-payroll-deductions-work): Understand what comes out of your pay: income tax, National Insurance, pension, and student loan deductions explained. - [How Savings Interest Works in the UK](https://korvaix.com/guides/how-savings-interest-works-in-the-uk): Everything you need to know about savings interest rates, compound interest, AER, and the Personal Savings Allowance. - [How Student Loan Repayments Work in the UK](https://korvaix.com/guides/how-student-loan-repayments-work): Everything you need to know about student loan repayments: thresholds, rates, plan types, and how much you will actually repay each month. - [How to Add or Remove VAT from a Price](https://korvaix.com/guides/how-to-add-or-remove-vat): A clear guide to adding VAT to a net amount and removing VAT from a gross amount, with common mistakes to avoid. - [How to Calculate Fuel Cost Per Journey](https://korvaix.com/guides/how-to-calculate-fuel-cost-per-journey): A simple guide to working out how much any car journey costs in fuel, with tips for reducing your fuel costs. - [How to Calculate ROI on Any Investment](https://korvaix.com/guides/how-to-calculate-roi-on-any-investment): A practical guide to calculating return on investment for marketing, property, stocks, and business decisions. - [How to Calculate Your Break-Even Point](https://korvaix.com/guides/how-to-calculate-break-even-point): Learn how to work out the break-even point for your business: the number of units or revenue needed to cover all your costs. - [How to Calculate Your Commute Cost](https://korvaix.com/guides/how-to-calculate-commute-costs): Work out the true cost of commuting by car including fuel, parking, and tolls, plus how hybrid working affects your spending. - [How to Calculate Your Freelance Day Rate](https://korvaix.com/guides/how-to-calculate-your-freelance-day-rate): A practical guide to setting your day rate as a freelancer or contractor, including salary equivalence and market benchmarks. - [How to Calculate Zakat](https://korvaix.com/guides/how-to-calculate-zakat): A plain-English guide to calculating Zakat: nisab, hawl, zakatable assets, deductible liabilities, and a worked GBP example. - [How to Estimate Your Energy Bill](https://korvaix.com/guides/how-to-estimate-your-energy-bill): Understand how energy bills are made up, what unit rates and standing charges mean, and how to estimate your monthly costs. - [How to Work Out Electricity Costs for Any Appliance](https://korvaix.com/guides/how-to-work-out-electricity-costs): A simple guide to calculating how much any appliance costs to run, with common examples and money-saving tips. - [Inside IR35 Explained: What UK Contractors Need to Know](https://korvaix.com/guides/inside-ir35-explained): A clear guide to working inside IR35, how it affects your take-home pay, and what it means for your contract. - [Inside vs Outside IR35 Explained](https://korvaix.com/guides/inside-vs-outside-ir35-explained): Understand the difference between inside and outside IR35, and how it affects your take-home pay as a contractor. - [Markup vs Margin Explained](https://korvaix.com/guides/markup-vs-margin-explained): Understand the difference between markup and margin, why it matters, and how to use each when pricing your products. - [Mounjaro vs Wegovy for Weight Loss](https://korvaix.com/guides/mounjaro-vs-wegovy-for-weight-loss): A balanced comparison of Mounjaro (tirzepatide) and Wegovy (semaglutide) — mechanism, effectiveness, cost, and side effects. - [Outside IR35 Explained for UK Contractors](https://korvaix.com/guides/outside-ir35-explained): What outside IR35 means, how it affects your take-home pay, and the key differences between inside and outside IR35. - [Profit Margin vs Markup Explained: What Every Business Needs to Know](https://korvaix.com/guides/profit-margin-vs-markup-explained): Understand the critical difference between margin and markup, and learn which to use for pricing, reporting, and profitability analysis. - [Redundancy Pay Rights in the UK Explained](https://korvaix.com/guides/redundancy-pay-rights-uk): A plain-English UK guide to statutory redundancy pay: who qualifies, how it is calculated, the GB and NI weekly caps, the relevant date, notice pay, and tax. - [Returning to Work After Maternity Leave: A Financial Guide](https://korvaix.com/guides/return-to-work-after-maternity): A practical guide to understanding the financial implications of returning to work after maternity leave, including childcare costs, tax implications, and support available. - [Should I Overpay My Mortgage or Save?](https://korvaix.com/guides/should-i-overpay-my-mortgage-or-save): When mortgage overpayments make sense, when saving is better, and how to compare the two options. - [Surface Area Formulas for Common 3D Shapes](https://korvaix.com/guides/surface-area-formulas-explained): A clear, plain-English guide to surface area formulas for sphere, cube, cone, cylinder, rectangular tank, capsule, spherical cap, conical frustum, ellipsoid and square pyramid — with worked examples in metric and imperial units. - [Tax-Free Childcare vs Other Support: Which Is Best for You?](https://korvaix.com/guides/tax-free-childcare-vs-other-support): Compare Tax-Free Childcare with Universal Credit childcare, childcare vouchers, and free hours to find the best option for your family. - [Understanding Etsy Fees for UK Sellers](https://korvaix.com/guides/understanding-etsy-fees-for-uk-sellers): A complete breakdown of every fee Etsy charges UK sellers, with strategies to price profitably. - [What BMI Means for Weight-Loss Injections](https://korvaix.com/guides/what-bmi-means-for-weight-loss-injections): How BMI is used to assess eligibility for weight-loss medications like Mounjaro and Wegovy, and its limitations. - [What is ROAS? Return on Ad Spend Explained](https://korvaix.com/guides/what-is-roas): A plain-English guide to ROAS: what it means, how to calculate it, what counts as a good ROAS, and how it differs from ROI. ## Generators - [Barcode Generator](https://korvaix.com/generators/barcode-generator) - [Username Generator](https://korvaix.com/generators/username-generator) - [Passphrase Generator](https://korvaix.com/generators/passphrase-generator) - [Password Generator](https://korvaix.com/generators/password-generator) - [Uuid Generator](https://korvaix.com/generators/uuid-generator) - [Qr Code Generator](https://korvaix.com/generators/qr-code-generator) - [Random Number Generator](https://korvaix.com/generators/random-number-generator) - [Email Signature Generator](https://korvaix.com/generators/email-signature-generator) - [Receipt Generator](https://korvaix.com/generators/receipt-generator) - [Invoice Generator](https://korvaix.com/generators/invoice-generator) - [Quote Generator](https://korvaix.com/generators/quote-generator) ## Text tools - [Text tools index](https://korvaix.com/tools/text-tools) - [Case converter](https://korvaix.com/tools/case-converter) - [Character counter](https://korvaix.com/tools/character-counter) - [Text cleaner](https://korvaix.com/tools/text-cleaner) ## Optional - [Sitemap (XML)](https://korvaix.com/sitemap.xml): Machine-readable list of every indexable URL. - [Privacy policy](https://korvaix.com/privacy) - [Terms of use](https://korvaix.com/terms) - [Disclaimer](https://korvaix.com/disclaimer)