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Math Calculators

Rectangular Prism Calculator

Verified formula Updated Jun 2026 Private — runs on your device

Enter details
units
units
units
Verified formula Private

Volume

60.0000

Surface area
94.0000
Space diagonal
7.0711

For general information only — not financial, tax, legal or medical advice. Verify before you rely on it.

How to use the Rectangular Prism Calculator

The Rectangular Prism Calculator works out your volume, along with 2 related figures in an instant. Enter length, width and height and the result updates as you type — it is free, needs no sign-up, and runs entirely in your browser so your figures stay private.

  1. Enter the length.
  2. Enter the width.
  3. Enter the height.
  4. Read off your volume, together with surface area and space diagonal — the calculator updates automatically, with no button to press.

Formula

The Rectangular Prism Calculator uses the formula:

Volume = Length × Width × Height

Worked example

For example, with length of 5 units, width of 4 units and height of 3 units, the volume is 60.0000.

Inputs used
Length 5 units
Width 4 units
Height 3 units
Results
Volume 60.0000
Surface area 94.0000
Space diagonal 7.0711

Results are estimates for educational use, not professional advice.

Key terms explained

Surface area
The total area of all the outer faces of a three-dimensional object.
Volume
The amount of three-dimensional space an object occupies, measured in cubic units.
Area
The amount of two-dimensional space a shape covers, measured in square units.

Frequently asked questions

Multiply length, width and height: V = l × w × h. A 5 × 4 × 3 box has a volume of 60 cubic units.

Add the areas of all six faces: 2(lw + lh + wh). For 5 × 4 × 3 that is 94 square units.

The longest internal diagonal is √(l² + w² + h²). For 5 × 4 × 3 it is about 7.07 units.

Yes. A rectangular prism, cuboid and rectangular box all describe a six-faced solid whose faces are rectangles.

The Rectangular Prism Calculator uses the formula: Volume = Length × Width × Height. For example, with length of 5 units, width of 4 units and height of 3 units, the volume is 60.0000.

Enter the length. Enter the width. Enter the height. Read off your volume, together with surface area and space diagonal — the calculator updates automatically, with no button to press.

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