Density Calculator
Density, mass or volume from the other two, in metric and US units, with the density in every common unit and specific gravity against a reference you enter.
The missing one of ρ, m and V, the density in kg/m³, g/cm³, lb/ft³, lb/gal and more, and specific gravity against your reference — exact unit definitions, no material table.
Example: 2.7 kg in 1 L is 2.7 g/cm³ = 2,700 kg/m³ = 168.6 lb/ft³ (specific gravity 2.7 against 1 g/cm³); 100 lb of a 62.4 lb/ft³ liquid occupies 1.60 ft³.
ρ = m / V,
with exact unit factors.
How the conversions are done, what specific gravity means here, and why no material list is included.
The arithmetic
Density is mass divided by volume. Whichever of the three you leave blank is solved from the other two, after converting both to SI (kilograms and cubic metres) and back. The unit factors are definitions, not measurements: 1 lb = 0.453 592 37 kg, 1 in = 0.0254 m, 1 US gallon = 231 in³, 1 L = 0.001 m³.
Specific gravity
Specific gravity is the density divided by a reference density — usually water at a stated temperature. The reference is a field you fill in (water is 0.9982 g/cm³ at 20 °C and 1.000 at 4 °C per the CRC Handbook) because the ratio depends on which reference you choose.
No material table
Densities vary with temperature, alloy, moisture and whether the volume counts voids (bulk versus true density for powders, soils and timber). A single "typical" figure would be wrong for your case as often as right, so the page takes yours and shows the arithmetic. Nothing leaves the browser; the same four anonymous usage counts as the rest of the site apply.
SOURCES
Last reviewed 20 September 2026. How results are checked: How we verify.