Rectangular Prism Surface Area Calculator
Calculate the surface area of a rectangular prism (cuboid) by entering the length, width, and height. A rectangular prism has 6 rectangular faces.
📋 Rectangular Prism Surface Area
Formula
Rectangular Prism Surface Area Formulas
Surface Area
Sum of all 6 rectangular face areas
Volume
Length times width times height
Face Diagonal
Diagonal across the base face
Space Diagonal
Diagonal through the center of the prism
Rectangular Prism Surface Area Examples
Example 1: Small Prism
Given: Length = 4 cm, Width = 3 cm, Height = 2 cm
Formula: SA = 2(lw + lh + wh)
Solution: SA = 2(4×3 + 4×2 + 3×2) = 2(12 + 8 + 6) = 2×26 = 52 cm²
Example 2: Medium Prism
Given: Length = 6 cm, Width = 4 cm, Height = 5 cm
Formula: SA = 2(lw + lh + wh)
Solution: SA = 2(6×4 + 6×5 + 4×5) = 2(24 + 30 + 20) = 2×74 = 148 cm²
Example 3: Large Prism
Given: Length = 10 cm, Width = 8 cm, Height = 6 cm
Formula: SA = 2(lw + lh + wh)
Solution: SA = 2(10×8 + 10×6 + 8×6) = 2(80 + 60 + 48) = 2×188 = 376 cm²
Rectangular Prism Surface Area FAQ
What is a rectangular prism?
A rectangular prism (also called a cuboid) is a 3D shape with 6 rectangular faces. Opposite faces are identical and parallel. Examples include boxes, books, and bricks.
How do you calculate rectangular prism surface area?
Use the formula SA = 2(lw + lh + wh), where l is length, w is width, and h is height. This accounts for all 6 faces.
Why is the formula 2(lw + lh + wh)?
There are 3 pairs of identical faces: top/bottom (lw), front/back (lh), and left/right (wh). Each pair contributes 2 times its area to the total.
What's the difference between a rectangular prism and a cube?
A cube is a special rectangular prism where all dimensions are equal (l = w = h). A rectangular prism can have different length, width, and height.