What is a rectangular prism?

A rectangular prism (also called a cuboid) is a 3D solid with six rectangular faces, where every pair of opposite faces is identical. A standard cardboard box is a common example.

What is the formula for surface area of a rectangular prism?

SA = 2(lw + lh + wh), where l is length, w is width, and h is height. This sums the area of all six faces.

What units does this calculator use?

You can enter dimensions in any unit (cm, m, inches, feet, etc.). The result will be in the square of that unit. Make sure all three dimensions use the same unit.

What is the difference between surface area and volume?

Surface area measures the total area of all outer faces (in square units), while volume measures the space inside the prism (in cubic units, V = l x w x h).

Can I calculate the area of just one face?

Yes. The three unique face areas are shown in the breakdown: lw (top/bottom), lh (front/back), and wh (left/right). Each pair area is double the single-face area.

Surface Area of a Rectangular Prism Calculator

Name: Surface Area of a Rectangular Prism Calculator
Availability: InStock
Author: Nham Vu

Enter the length, width, and height of a rectangular prism to instantly calculate its total surface area.

Rectangular Prism Dimensions

Length (l)

Width (w)

Height (h)

Unit (optional label)

Formula

SA = 2(lw + lh + wh)

Enter length, width, and height to see the result

Copied!

Summary

Enter the length, width, and height of a rectangular prism to instantly calculate its total surface area.

How it works

A rectangular prism has six rectangular faces arranged in three opposite pairs. Each pair shares identical dimensions: two lw faces (top and bottom), two lh faces (front and back), and two wh faces (left and right). The total surface area is the sum of the areas of all six faces: SA = 2(lw + lh + wh).

Use cases

Estimate how much wrapping material is needed to cover a box.
Calculate the amount of paint required to coat a rectangular container.
Determine the material cost for manufacturing rectangular packaging.
Verify surface area homework answers for geometry class.
Compute heat dissipation area for rectangular electronic enclosures.

Frequently Asked Questions

Last updated: 2026-05-23 · Reviewed by Nham Vu