Geometry calculator

Surface Area Calculator

Find exterior area for coating, heat transfer, packaging, and geometry checks.

Use calculator View formulas FAQ

Calculator

Enter dimensions

Select a shape where available, choose units, and read the result as dimensions update.

Geometry

Solid shape
Length m
Width m
Height m
Side length m
Radius m
Slant height m

Result

About this calculator

How it works

Surface area is the total exterior area of a 3D object. It is useful for coatings, insulation, heat transfer, printing, packaging, and material estimates.

Formulas

Formulas used

Rectangular prism

SA = 2(lw + lh + wh)

Cube

SA = 6s^2

Cylinder

SA = 2 pi r (r + h)

Sphere

SA = 4 pi r^2

Cone

SA = pi r (r + l)

Worked example

Example: closed cylinder

For a closed cylinder with radius 0.20 m and height 0.80 m:

Surface area

SA = 2 pi x 0.20 x (0.20 + 0.80) = 1.257 m2

Volume check

V = pi x 0.20^2 x 0.80 = 0.1005 m3

Guide

How to use this calculator

Select the shape or section type if a shape menu is shown.
Enter the known dimensions and choose units beside each length input.
Read the highlighted result first, then use the supporting values for related checks.

Reference

What the results mean

Surface area

The total exterior area of the selected solid.

Volume check

The enclosed volume, included for context where useful.

Assumptions and limits

Before using the result

Inputs are treated as ideal geometric dimensions with no tolerance, chamfer, fillet, draft, roughness, or manufacturing allowance.
Section properties are centroidal for the listed standard shapes and do not include rotation, offsets, or parallel-axis corrections.
Use project drawings, tolerances, material data, and applicable design standards for final engineering work.

FAQ