Surface Area Calculator

Understanding Surface Area

The **Surface Area** of a three-dimensional object is a measure of the total area that the surface of the object occupies.

Solids Formulas

• Sphere: $\text{SA} = 4\pi r^2$
• Cylinder: $\text{SA} = 2\pi r^2 + 2\pi rh$
• Cone: $\text{SA} = \pi r^2 + \pi r \sqrt{r^2 + h^2}$
• Cube: $\text{SA} = 6s^2$
• Rectangular Prism: $\text{SA} = 2(lw + lh + wh)$
• Triangular Prism: $\text{SA} = ab + (a + b + c)L$, where $a, b, c$ are the sides of a right triangular base, or using Heron's formula for the general triangular base.
• Square Pyramid: $\text{SA} = s^2 + 2s \sqrt{(s/2)^2 + h^2}$