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Density, Mass, Volume & Box Dimensions

Solve average density, mass or volume, with optional length, width and height for a rectangular solid.

  • 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.

Private by default

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

Formula and method

A 2 m × 3 m × 4 m rectangular solid occupies 24 m³. With mass 48 kg, its average density is 2 kg/m³.

Density = mass / volume; rectangular volume = length × width × height

Worked example

Enter these known values and leave the other values blank.

Rectangular length
2 m
Rectangular width
3 m
Rectangular height
4 m
Mass of the material or object
48 kg
Average mass density
2 kg/m³
Total volume
24 m³

Assumptions and limitations

  • Mass, density, volume and supplied dimensions are positive. Density here means mass per volume, not weight force per volume.
  • Length × width × height applies only to a rectangular solid. For a different shape, enter its measured or separately calculated volume.
  • For a porous or hollow object, state whether the chosen volume includes voids. The result is the average density for that volume convention.

Common questions

Do I need all three dimensions?

No. If volume is already known, enter it directly. The dimensions provide an optional rectangular-volume calculation.

Why does g/cm³ differ from kg/m³?

One gram per cubic centimeter equals 1,000 kilograms per cubic meter. Both mass and volume units contribute to the conversion.

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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