Rectangular prism volume calculator

Calculate the volume of a rectangular prism or cuboid from length, width and height. Use matching units for the three edges and check a worked example.

Result

Three directions, one volume

Change one dimension at a time. Horizontal sections have the same area as the base; the space diagonal joins two opposite corners through the solid. Move the slider from bottom to top: the section area stays the same.

How do you calculate cuboid volume?

Multiply length, width and height. The rectangular base area times the height gives the space enclosed.

V = l \times w \times h

How to use the calculator

Enter measurements with a decimal point or comma: results update immediately. Input units apply to every length; changing them converts the measurements. Changing result units leaves the shape unchanged. The control below the drawing reveals or hides its visual explanation. Copy results includes valid measurements and the result. Reset and Try this example restore the initial values and centimetre units.

The first formula shows the relationship; the second substitutes measurements converted to the result unit. The ≈ sign indicates rounding, including in the substituted values.

Measure a box

A box measuring 5 × 3 × 2 cm inside holds 30 cm³. Use internal measurements when you want usable space.

From measurements to the result

Input: $l = 5 cm; w = 3 cm; h = 2 cm$
Result: $30 {cm}^{3}$

Calculation steps

Calculate the rectangular base area.
$B = 5 \times 3 = 15$
Complete the calculation using the tool’s formula.
$V = 15 \times 2 = 30$

Units and interpretation

Volume uses cubic units: 1 m³ = 1,000,000 cm³ = 1,000 L. Capacity in litres is geometric; use internal measurements for real containers.

The three dimensions are perpendicular. Walls and dividers are not subtracted.

Precision and numerical limits

Lengths range from 0 to 10¹² in the selected unit; triangle sides must be strictly positive. Results use two decimal places, with scientific notation for very small or large values. Calculations use browser precision: unrepresentable positive values produce an error. A rejected unit change keeps the previous data. Calculation takes place in your browser.

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Rectangular prism volume calculator

Result

Three directions, one volume

How do you calculate cuboid volume?

How to use the calculator

Measure a box

From measurements to the result

Calculation steps

Units and interpretation

You might also need

Circle area

Circle circumference

Triangle area