Free · Mechanics and material properties

Mass from Density, Volume or Box Dimensions

Calculate mass from density and entered volume or rectangular dimensions, with reverse density and volume calculations.

  • Formula & worked example
  • Private in your browser
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Calculator inputs

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How to use this calculator

  1. Enter the known values in the units shown. Results update as you type.
  2. Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
  3. Use the worked example to check the method. Reset restores the starting fields.

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Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

Formula and method

A 10 cm by 20 cm by 30 cm box has volume 0.006 m³. At density 1,000 kg/m³, its mass is 6 kg.

Mass = density × volume; rectangular volume = length × width × height

Worked example

Enter these known values and leave the other values blank.

Uniform mass density
1000 kg/m³
Box length
10 cm
Box width
20 cm
Box height
30 cm
Material volume
0.006 m³
Mass
6 kg

Assumptions and limitations

  • The result is mass, measured in kg, lb or another mass unit. Gravitational force requires a separate gravity factor.
  • Density and occupied volume are positive. Density is uniform over the modeled material.
  • Rectangular dimensions describe the occupied volume; cavities, voids and packaging are not subtracted automatically.

Common questions

Is this weight as a force?

No. Density times volume gives mass. Force in newtons would be mass times gravitational acceleration.

Must the object be a box?

Only when deriving volume from three dimensions. Enter a known volume directly for another shape.

References

The US fluid ounce uses one 128th of the exact US liquid gallon, replacing the rounded captured reciprocal factor. The US customary cup uses one sixteenth of the exact US liquid gallon, replacing the rounded captured cup volume. Bookify replaces the captured rounded US gallon with the exact 3.785411784-liter definition. Bookify uses exact customary mass and volume definitions for density units, replacing rounded factors in the reference.

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