Density Calculator

Density = mass ÷ volume (ρ = m/V). If a 200 g object occupies 50 cm³, its density is 200 ÷ 50 = 4 g/cm³. This calculator handles unit conversions for you and reports the result in g/cm³, kg/m³, and lb/ft³.

Pure water is about 1 g/cm³ (1,000 kg/m³) at 4°C. It is the reference point for whether something floats: objects less dense than water float, and denser ones sink. Seawater is slightly denser at about 1.025 g/cm³.

1 g/cm³ = 1,000 kg/m³ = 62.43 lb/ft³. Grams per cubic centimeter and grams per milliliter are the same thing (1 cm³ = 1 mL). This tool shows all three common units at once.

Density identifies materials, predicts whether things float or sink, and is used in engineering, chemistry, shipping, and cooking. For example, gold (19.3 g/cm³) is far denser than aluminum (2.7), so density helps spot fakes.

Yes. Most substances expand when heated, so their density decreases as temperature rises (volume grows while mass stays the same). Water is a famous exception near freezing. For precise work, note the temperature of your measurement.