Density Calculator
Solve ρ = m ÷ V for density, mass or volume with unit menus (g, kg, lb, mL, L, m³, ft³, g/cm³, lb/ft³ and more), a table of common material densities, specific gravity, sink-or-float and the worked steps.
How it works
ρ = m ÷ V · m = ρ × V · V = m ÷ ρ · 1 g/cm³ = 1 g/mL = 1 kg/L = 1,000 kg/m³ ≈ 62.43 lb/ft³
Density is mass per unit volume — how much matter is packed into a given space. Pick what you want to find under "Solve for": density from mass and volume, mass from density and volume, or volume from mass and density. Each field has its own unit menu, so you can type grams and millilitres, pounds and cubic feet, or kilograms and cubic metres; everything is converted to SI (kg and m³) for the working and then shown in the unit you choose under "More options". For mass or volume problems you can type a density or pick a material such as water, steel or concrete. The results also give specific gravity (density relative to water at 4 °C), whether the object would sink or float in fresh water, and the closest common material, which is a quick sense check on your units.
Worked example
A 500 g block measures 250 cm³: ρ = 0.5 kg ÷ 0.00025 m³ = 2,000 kg/m³, or 2 g/cm³ — a little less dense than glass, so it sinks. Going the other way, 4 m³ of aluminium at 2,700 kg/m³ has a mass of 2,700 × 4 = 10,800 kg, and 448 g of copper at 8.96 g/cm³ fills 448 ÷ 8.96 = 50 cm³.
Frequently asked questions
What is the density of water?
Pure water is about 1,000 kg/m³, or 1 g/cm³, at 4 °C, and about 998 kg/m³ at 20 °C. Materials denser than water sink in it and less dense ones float.
How do I convert kg/m³ to g/cm³?
Divide by 1,000. So 2,700 kg/m³ (aluminium) is 2.7 g/cm³. g/cm³, g/mL and kg/L are all the same number. To get lb/ft³, divide kg/m³ by 16.018.
How do I find mass or volume from density?
Rearrange ρ = m ÷ V: mass = density × volume, and volume = mass ÷ density. Choose Mass or Volume under "Solve for" and the calculator does the rearranging and the unit conversion for you.
What is specific gravity?
Specific gravity is a material's density divided by the density of water (1,000 kg/m³ at 4 °C), so it has no units. A specific gravity above 1 means the material sinks in fresh water.
Does temperature affect density?
Yes. Most materials expand when heated, increasing volume and lowering density. Gases are also very sensitive to pressure. For precise work, quote the temperature (and for gases the pressure) at which the density was measured.
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Educational estimate. Check the formula and units for your exact case.