What formulas does this calculator use?

Volume = length × width × height; Surface area = 2(lw + lh + wh); Diagonal = √(l² + w² + h²).

What's another name for a cuboid?

It's also called a rectangular prism or rectangular box — any box shape with six rectangular faces.

How is a cuboid different from a cube?

A cube is a special case of a cuboid where all three dimensions (length, width, height) are equal.

Cuboid Calculator - CalculatorLabs.net

Cuboid Calculator

A cuboid (also called a rectangular prism or box) is a 3D shape with six rectangular faces, like a shoebox, a brick, or a shipping container.

Length (l)

Width (w)

Height (h)

Instant Result

Volume -

Surface Area -

Space Diagonal -

What Is a Cuboid (Rectangular Prism) Calculator?

A cuboid (also called a rectangular prism or box) is a 3D shape with six rectangular faces, like a shoebox, a brick, or a shipping container. This calculator finds the volume, total surface area, and the space diagonal (the longest straight line inside the box) from its length, width, and height.

How to Use This Cuboid (Rectangular Prism) Calculator

Measure the length, width, and height of the box.
Enter all three values into the fields above.
Click Calculate to get the volume, surface area, and diagonal instantly.
All three dimensions must use the same unit for an accurate result.

Formula

Volume = l × w × h
Surface Area = 2(lw + lh + wh)
Space Diagonal = √(l² + w² + h²)

Worked Example

A storage box measures 40 cm long, 30 cm wide, and 25 cm tall. Volume = 40 × 30 × 25 = 30,000 cm³. Surface Area = 2(40×30 + 40×25 + 30×25) = 2(1200+1000+750) = 5,900 cm². Space Diagonal = √(40² + 30² + 25²) ≈ 56.79 cm.