Density calculator
Calculate density from mass and volume (d = m ÷ V), in g/cm³ and kg/m³.
How the calculation works
Density relates mass and volume:
d = mass ÷ volume
In g/cm³, water is ~1. Materials denser than water sink; less dense ones float. 1 g/cm³ = 1000 kg/m³.
Examples
- 200 g in 250 cm³: d = 0.8 g/cm³ → floats on water.
- Iron is ~7.87 g/cm³; it sinks (denser than water).
Frequently asked questions
How do I find the mass or volume?
Rearrange the formula: mass = density × volume, and volume = mass ÷ density.
Why do things float?
An object floats when it is less dense than the liquid. Below 1 g/cm³ it floats on water; above, it sinks.
Are density and weight the same?
No. Weight depends on size; density is mass per volume — a property of the material, independent of size.
Why does a steel ship float?
Because average density of the whole vessel matters, not the steel alone — the hull encloses a large volume of air.
Why does ice float?
Ice has a density of 0.92 against water's 1.00 — an anomaly, since most substances get denser when solid.
Does density change with temperature?
Yes, it falls as temperature rises. Water peaks in density at 4 °C, not at 0 °C.
How do I convert g/cm³ to kg/m³?
Multiply by 1,000. Water is 1 g/cm³, or 1,000 kg/m³ — a cubic metre of water weighs a tonne.
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Updated on June 30, 2026 · by Rafael Rossi · Methodology & sources