This density calculator finds density, mass or volume when you know the other two. It works in g/cm³ or kg/m³ and also converts to lb/ft³.
Density formula
Density (ρ) = mass ÷ volume, so mass = density × volume and volume = mass ÷ density.
1 g/cm³ equals 1,000 kg/m³. Water has a density of about 1 g/cm³, so anything denser sinks and anything less dense floats.
Worked example
A block weighs 270 g and has a volume of 100 cm³. Its density is 270 ÷ 100 = 2.7 g/cm³ (2,700 kg/m³), which matches aluminum.
Frequently asked questions
How do I measure the volume of an irregular object?
Submerge it in a measuring container of water. The rise in water level is the object’s volume (1 mL = 1 cm³).
Does temperature affect density?
Yes. Most materials expand when heated, so their density falls slightly. Water is densest at about 4°C.