Density Converter
Convert kg/m³, g/cm³, lb/ft³, and other density units.
Enter a value, choose the units, and see the result plus every other density unit.
Kilogram per cubic meter → Gram per cubic centimeter
Density Converter
Density tells you how much mass fits in a given volume. This converter switches between SI units (kg/m³, g/cm³, g/mL, g/L, kg/L, mg/L) and US units (lb/ft³, lb/in³, lb/gal, oz/in³, slug/ft³), which is useful for materials engineering, chemistry labs, fuel handling, and water quality reports.
Unit relationships
| Unit | kg/m³ |
|---|---|
| 1 g/cm³ = 1 g/mL = 1 kg/L | 1,000 |
| 1 g/L | 1 |
| 1 mg/L | 0.001 |
| 1 lb/ft³ | 16.0185 |
| 1 lb/US gal | 119.8264 |
| 1 slug/ft³ | 515.3788 |
| 1 lb/in³ | 27,679.9047 |
Because a gram per liter equals a kilogram per cubic meter, air at sea level (1.225 kg/m³) is also 1.225 g/L.
Common material densities
| Material | g/cm³ | lb/ft³ |
|---|---|---|
| Water | 1.000 | 62.43 |
| Seawater | 1.025 | 63.99 |
| Aluminum | 2.70 | 168.56 |
| Steel | 7.85 | 490.06 |
Engineering example
A structural engineer given steel at 7,850 kg/m³ can convert it to 490.06 lb/ft³ for a US load calculation, or to 0.2836 lb/in³ for machined parts. Gold, at 19.32 g/cm³, is 0.698 lb/in³.
Fuel and liquids
Fuel is often priced by volume but shipped by weight. Gasoline at about 0.74 g/mL weighs roughly 6.18 lb per US gallon, while water weighs 8.345 lb/gal. Environmental labs report dissolved substances in mg/L, which for dilute water solutions is approximately parts per million.
From density to mass or volume
Once you know the density, mass = density × volume. Convert the volume with the Volume Converter, compute the mass, and then express it in kilograms or pounds with the Weight Converter.
Frequently Asked Questions
How do I convert g/cm³ to kg/m³?
Multiply by 1,000. One gram per cubic centimeter equals 1,000 kilograms per cubic meter, so steel at 7.85 g/cm³ is 7,850 kg/m³.
Are g/cm³ and g/mL the same?
Yes. One cubic centimeter is exactly one milliliter, so 1 g/cm³ = 1 g/mL = 1 kg/L = 1,000 kg/m³.
What is the density of water in lb/ft³?
Water at about 4 °C has a density of roughly 1,000 kg/m³, which is 62.43 lb/ft³ or 8.345 lb per US gallon.
How do I find mass from density and volume?
Multiply density by volume using matching units: mass = density × volume. For example, 2 m³ of a 1,000 kg/m³ liquid has a mass of 2,000 kg.