Surface Area accuracy and testing

Formula source

• Formulas vary by shape: * **Cube:** $6 \times side^2$ (6 faces) * **Sphere:** $4 \times \pi \times r^2$ * **Cylinder:** $(2 \pi r^2) + (2 \pi r h)$ (2 circular bases + curved side) * **Cone:** $\pi r (r + \sqrt{h^2 + r^2})$ (Base area + Lateral area)

Test cases

Known limitations

• This page documents the checked-in calculator logic and does not certify results for every real-world edge case.
• Use the result as a planning estimate unless the calculator page states a stricter purpose.

Assumptions

• All measurements are entered in the same linear unit, and the result is returned in square units.
• This calculator assumes closed solids, so top and bottom faces are included where applicable.
• Dimensions are treated as non-negative geometric lengths.

Unit handling

• Shape accepts one of the configured options.
• Radius (r) accepts numeric values.
• Height (h) accepts numeric values.
• Side Length (l) accepts numeric values.

Rounding rules

• Number displays use up to 2 decimal places in the calculator UI.

Version history

Change log