🧱Density Calculator

About this tool

Choose whether to solve for density, mass or volume, then enter the other two values with their units, from grams and kilograms to pounds, and from millilitres to cubic feet and gallons. The calculator converts the result to kg/m³, g/cm³ and lb/ft³, says whether the object would float in fresh water, and names the closest common material from a reference table.

How to calculate density

Density is mass divided by volume, ρ = m ÷ V. Rearranged, mass = density × volume and volume = mass ÷ density. A 500 g object with a volume of 200 cm³ has a density of 2.5 g/cm³, or 2,500 kg/m³, close to glass. Water has a density of about 1 g/cm³ at 4°C, so 1 g/cm³ = 1 g/mL = 1 kg/L = 1,000 kg/m³ ≈ 62.4 lb/ft³. Anything with a lower average density floats in water. Ice, at about 917 kg/m³, floats with roughly 90% below the surface, and a steel ship floats because its hull encloses so much air that its average density is lower than water's. To find the volume of an irregular object, submerge it and measure the water it displaces. Typical values include cork at about 240 kg/m³, aluminium 2,700, steel 7,850, lead 11,340 and gold 19,300. Honest limits: density changes with temperature and pressure, especially for gases and liquids, and woods, alloys and plastics vary widely, so the table gives typical values only. The volume calculator works out volumes of shapes and the unit converter converts mass and volume units.

Frequently asked questions