Density Unit Converter
Convert density between kg/m³, g/cm³, lb/ft³, lb/in³ and other units.
How to use this calculator
- 1Enter the value you want to convert.
- 2Pick the unit you are converting from and the one you want.
- 3The table below shows the same value in every other supported unit.
How the calculation works
result = (value × factor(from) ) / factor(to)- factor
- How many kilograms per cubic metre one unit represents
Every value is converted to kilograms per cubic metre first, then out to the target unit. This means n units need n factors rather than n² conversion pairs.
Density is mass per unit volume, so every unit here is a mass unit divided by a volume unit — and each conversion factor is the mass factor divided by the cube of the length factor.
Because water is almost exactly 1,000 kg/m³, the g/cm³ figure for any material is numerically equal to its specific gravity (its density relative to water). Steel at 7.85 g/cm³ has a specific gravity of 7.85.
Worked example
1 gram per cubic centimetre to kilogram per cubic metre
- 1.One gram per cubic centimetre is 1,000 kilograms per cubic metre, so 1 g/cm³ is 1,000 kilograms per cubic metre.
- 2.One kilogram per cubic metre is 1 kilograms per cubic metre, so divide: 1,000 ÷ 1 = 1,000.
- 3.Put another way, 1 g/cm³ = 1,000 kg/m³.
Result: 1,000 kg/m³
What this assumes, and where it stops
Assumptions
- Conversion factors follow the internationally agreed definitions of each unit.
Limitations
- Results are computed in double-precision floating point, which is exact to about 15 significant figures.
- Very large or very small values are displayed in scientific notation to avoid misleading precision.
Common questions
Is g/cm³ the same as specific gravity?
Numerically, near enough for most purposes. Specific gravity is density relative to water, and water is almost exactly 1 g/cm³, so a material at 2.7 g/cm³ has a specific gravity of about 2.7. The difference is that specific gravity is a ratio with no units, and it depends slightly on the reference temperature used for water.
Why is 1 g/cm³ equal to 1,000 kg/m³?
Because there are 1,000 grams in a kilogram and 1,000,000 cubic centimetres in a cubic metre. Dividing gives a factor of 1,000. The cube is what catches people out — a metre is 100 cm, but a cubic metre is 1,000,000 cm³.
Formula and content last reviewed on .
Results are estimates for information only, not professional advice.
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