Density Converter
Convert between kg/m³, g/cm³, g/mL, lb/ft³, and lb/gallon.
How density conversion works
Density is mass per unit of volume, so every unit here combines a mass unit (kilograms, grams, pounds) with a volume unit (cubic meters, cubic centimeters, cubic feet, gallons). Everything converts through kilograms per cubic meter, the SI unit.
Common conversions
- Water has a density of almost exactly 1,000 kg/m³ = 1 g/cm³ = 1 g/mL at 4°C
- 1 g/cm³ = 1,000 kg/m³ — grams-per-cc and kg-per-cubic-meter differ by exactly a factor of 1,000
- 1 lb/ft³ ≈ 16.02 kg/m³
Frequently asked questions
Why are g/cm³ and g/mL the same number?
Because a cubic centimeter and a milliliter are exactly the same volume by definition (1 cm³ = 1 mL) — so any density expressed in grams per cubic centimeter is numerically identical to grams per milliliter.
Why does water's density matter as a reference point?
Water's density (about 1,000 kg/m³) is used as the baseline for specific gravity, a common way materials are compared — a material with a specific gravity above 1 sinks in water, and below 1 it floats.