Area Calculator
Pick a 2D shape — circle, square, rectangle, triangle, trapezium, parallelogram, ellipse, regular polygon, rhombus, sector, annulus or kite — to open its…
What this calculator does
A hub page that links to dedicated area calculators for 12 common 2D shapes — each with its own formula, worked example, and breakdown.
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Related calculators
- Annulus Area Calculator — Enter the outer and inner radii. The calculator returns A = π·(R² − r²).
- Capsule Surface Area Calculator — Enter the radius and the straight middle length. The calculator returns 4πr² for the two rounded ends plus 2πrh for the cylindrical side.
- Circle Area Calculator — Enter the radius. The calculator returns A = πr², the area of the flat disc.
- Circular 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).
- Cone Surface Area Calculator — Enter the base radius and height. The calculator splits the answer into the base (πr²) and the lateral surface (πr·s), where s = √(r²+h²) is
- Conical Frustum Surface Area Calculator — Enter the top radius, bottom radius and height. The calculator returns lateral area π(r₁+r₂)·s plus the two end discs.
Related guides
- Surface Area Formulas for Common 3D Shapes — A clear, plain-English guide to surface area formulas for sphere, cube, cone, cylinder, rectangular tank, capsule, spherical cap, conical frustum, ellipsoid and