Cuboid Surface Area Calculator

Math

Calculate the surface area of a cuboid (rectangular prism) from its length, width, and height.

Formula

SA = 2(lw + lh + wh)
  • Surface Area = 2(lw + lh + wh) where l=length, w=width, h=height.
  • All 6 faces: 2 of lw, 2 of lh, 2 of wh.

Cuboid Surface Area Example

Inputs
  • Length: 5
  • Width: 4
  • Height: 3

Cuboid with length 5, width 4, height 3 has SA = 2(20+15+12) = 94 units².

Frequently asked questions

What is a cuboid?
A cuboid is a 3D shape with 6 rectangular faces, 12 edges, and 8 vertices.
How is surface area calculated?
SA = 2(lw + lh + wh) includes all 6 rectangular faces.
When would I use this?
For wrapping/packaging calculations, paint area needed, or designing boxes.
What's a cube?
A cube is a special cuboid where length = width = height.
How can I verify the calculation manually?
Use the displayed formula and work through the numbers step by step. If your manual result differs slightly, check rounding and unit conversions first.
Can I use this for planning and budgeting?
Yes. Run best-case, expected, and worst-case inputs to compare outcomes and make safer planning decisions.