Density Calculator

Density calculator at a glance#

A density calculator finds the density of a substance from its mass and volume. Density is mass divided by volume, written as the formula ρ = m/V. So 100 g of a material that takes up 50 cm³ has a density of 2 g/cm³. Rearrange the formula to get mass (m = ρV) or volume (V = m/ρ).

Density is reported in grams per cubic centimeter (g/cm³) or kilograms per cubic meter (kg/m³). Water is the common reference point: it is about 1 g/cm³, which is the same as 1000 kg/m³, so a substance denser than 1 g/cm³ sinks in water and a lighter one floats. To calculate density by hand, keep mass and volume in matching units, then divide the mass by the volume.

Enter your mass and volume in the calculator above for the exact density, and switch units there for pounds, kilograms, cubic inches, or cubic feet. Density shifts with temperature and pressure, so a measured value can differ slightly from a reference figure.

How to use the density calculator#

Enter the mass and the volume, choose your units, and the calculator returns the density using rho = m / V. It accepts grams, kilograms and pounds for mass, and cubic centimeters, cubic inches, cubic feet and cubic meters for volume, converting between them so the density comes out in the unit you pick.

Finding mass or volume instead#

The same formula solves for any of the three values. To find mass, multiply density by volume: m = rho x V. To find volume, divide mass by density: V = m / rho. Keep your units consistent so the result lands in the unit you expect.

Common density units#

Density is reported in grams per cubic centimeter (g/cm³), kilograms per cubic meter (kg/m³) or pounds per cubic foot (lb/ft³). Water is the standard reference: about 1 g/cm³, which equals 1000 kg/m³ or roughly 62.4 lb/ft³. Anything denser than water sinks, and anything lighter floats.

Temperature and pressure#

Density is not fixed. Most materials expand when heated, so their density drops as temperature rises. Water is densest near 4 °C and becomes slightly less dense as it warms. For gases, pressure matters too, which is why reference tables list a standard temperature and pressure.

Frequently asked questions#

How does a density calculator work?#

It divides mass by volume using rho = m / V. Enter 1000 g of water in a volume of 1000 cm³ (one liter) and it returns 1 g/cm³.

How do you calculate density if you know mass and volume?#

Divide the mass by the volume. For example, 500 g occupying 250 cm³ gives 500 / 250 = 2 g/cm³. Keep mass and volume in matching units before dividing.

What units is density measured in?#

The common units are grams per cubic centimeter (g/cm³), kilograms per cubic meter (kg/m³) and pounds per cubic foot (lb/ft³). Water is about 1 g/cm³, 1000 kg/m³, or 62.4 lb/ft³.

How does temperature affect density?#

Higher temperature usually lowers density, because materials expand as they warm. Water is an exception below 4 °C, where it is at its densest.

What does density tell me about floating or sinking?#

Compare the density to water at about 1 g/cm³. A material denser than 1 g/cm³ sinks in water; one less dense floats.