Density Calculator

The density formula

Density describes how much mass is packed into a given volume. The formula is ρ = m ÷ V, where ρ (rho) is density, m is mass and V is volume. If you know any two of the three values you can find the third: m = ρ × V and V = m ÷ ρ. A block with a mass of 500 g and a volume of 200 cm³ has a density of 2.5 g/cm³. This calculator converts everything to SI units internally, so you can mix units such as pounds and liters without doing the conversion by hand.

Using material presets

When solving for mass or volume you often need the density of a common material. The presets include water (1,000 kg/m³), ice, aluminum, steel, copper, lead, gold, oak, concrete, glass, air and mercury. Pick one and the density field fills in automatically, then enter the volume to find the mass, or the mass to find the volume. Real materials vary, for example with alloy, moisture content or temperature, so treat the presets as typical values and replace them if you have a datasheet.

Why density matters

Density tells you whether something floats, how heavy a shipment will be, and what material an unknown sample might be. Engineers use it to estimate the weight of metal parts and concrete pours, cooks use it to convert between volume and weight, and students use it in physics and chemistry labs. Remember that gases are strongly affected by temperature and pressure, and liquids expand slightly when heated. All of the calculation happens locally in your browser, with no data uploaded.

Example: a steel plate with a volume of 0.002 m³ and a density of 7,850 kg/m³ has a mass of 15.7 kg. Keep units consistent when you check results by hand, because 1 g/cm³ equals 1,000 kg/m³ and mixing them is the most common source of error.