Surface Area Calculator
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How surface area calculation works
Surface area measures the total area of all outer faces of a three-dimensional solid, always expressed in square units — in², ft², cm², m², etc. Unlike volume, which measures the space inside a shape, surface area measures how much material would be needed to cover it completely. Each geometric solid has a dedicated formula derived from its geometry. This calculator applies the exact formula and shows you the full working.
Frequently asked questions
Sphere surface area calculator
Use the sphere surface area calculator to find the surface area of any sphere. Formula: SA = 4 × π × r², where r is the radius. Example: a sphere with radius 3 cm has a surface area of 113.10 cm².
Cube surface area calculator
Use the cube surface area calculator to find the surface area of any cube. Formula: SA = 6 × s², where s is the side length. Example: a cube with side 4 ft has a surface area of 96 ft².
Rectangular prism surface area calculator
Use the rectangular prism surface area calculator. Formula: SA = 2(lw + lh + wh). Example: 5 × 4 × 3 inches → SA = 94 in².
Cylinder surface area calculator
Use the cylinder surface area calculator. Formula: SA = 2πr(r + h). Example: radius 3 in, height 10 in → SA = 244.92 in².
Cone surface area calculator
Use the cone surface area calculator. Formula: SA = πr(r + l), where l is the slant height. Example: radius 3 in, height 4 in → SA = 75.40 in².
Pyramid surface area calculator
Use the square pyramid surface area calculator. Formula: SA = b² + 2 × b × l, where b is the base side and l is the slant height.
Triangular prism surface area calculator
Use the triangular prism surface area calculator. Formula: SA = b×h + (s1 + s2 + s3) × l.
Capsule surface area calculator
Use the capsule surface area calculator. Formula: SA = 2πr(2r + h), where r is the radius and h is the cylinder height.