Math Calculators
Density Calculator
Density is mass divided by volume. Type any two of the three quantities — mass, volume, density — and this page solves the third, converting every unit from its exact definition. When density is the answer it is shown in g/cm³, kg/m³ and lb/ft³ together, beside a sourced reference table of common materials.
Calculator
Formula
Density is a derived quantity: it is not measured directly but computed from a mass and a volume, ρ = m ÷ V. Solving for either of the other two is the same equation rearranged — m = ρ × V and V = m ÷ ρ — which is why one page can answer all three questions. Units are handled before the arithmetic: every mass becomes kilograms and every volume becomes cubic metres through the definitional factors (1 in = 0.0254 m, 1 ft = 12 in, 1 lb = 0.45359237 kg, 1 L = 0.001 m³, 1 US gal = 3.785411784 L), and the answer is converted back into the unit you chose. 1 g/cm³ is exactly 1000 kg/m³, and one pound per cubic foot is 16.018463… kg/m³.
About This Calculator
What It Does
This page answers the relation between a substance's mass, its volume and its density — ρ = m ÷ V. Choose which of the three you want solved: give the mass and the volume and it returns the density, give the density and the volume and it returns the mass, give the density and the mass and it returns the volume. Every unit is converted from its exact definition before the arithmetic, and when density is the answer it is printed at once in g/cm³, kg/m³ and lb/ft³. A pick-list fills the density field from a table of common materials, and the table itself is shown so you can compare.
Worked Example
The page opens with 1 kilogram of water in 1 litre, and computes density = mass ÷ volume: 1 kg ÷ 0.001 m³ = 1000 kg/m³, which prints as 1 g/cm³ and as 62.427961 lb/ft³. Switch Find to Mass, keep 998.2071 kg/m³ — water at 20 °C, the pick-list's own row — and 1 litre, and the answer is 0.9982071 kg: the same water read the other way round.
Real-World Usage
Use it to check whether a piece of metal is the alloy it was sold as, to work out what a crate of a given volume will weigh before it ships, to compare two building materials before choosing one, or to turn a recipe's volume into a mass once you know what the ingredient is.
Local Context
Density is a property of the substance and not of the country, so nothing here changes with your location and the page serves one set of values everywhere. Two conventions are worth knowing. The metric ton in the mass control is the tonne of 1000 kg, not the US short ton of 2000 lb (907.18474 kg). And the gallon in the volume control is the US liquid gallon of 3.785411784 litres, not the imperial gallon of 4.54609 litres.
Sources and Methodology
Every value in the material table is a typical figure read from a published source, not a measurement taken on this page. Water, ice and ethanol come from the English-language Wikipedia articles “Density”, “Properties of water” and “Ethanol (data page)”; dry air from “Density of air”; aluminium, copper, lead and gold from “Densities of the elements (data page)”; mild steel from “Steel”, at the mid-point of its 7,750–8,050 kg/m³ range; oak and pine from “Wood”, each at 12 % moisture; soda–lime glass from “Soda–lime glass”; and structural concrete from GIGAcalculator's density-calculator worked example. All of these were read in October 2026, and every value is quoted at the table's reference condition of 20 °C and 101.325 kPa except the rows that state their own.
Last reviewed: October 2026.
Frequently Asked Questions
Why is my figure different from the value in a book?
Because a density moves with the sample. An alloy's composition, a timber's moisture content and any change in temperature all shift it: water is 999.84 kg/m³ at 0 °C, 998.21 kg/m³ at 20 °C and 958.4 kg/m³ at 100 °C. The reference table states the condition its values are quoted at, and they are typical figures rather than certified ones.
What happens at a different temperature?
The relation does not change — mass ÷ volume is still mass ÷ volume — but the volume does, so the density does with it. For a solid or a liquid the movement is small; for a gas it is large, because a gas expands to fill its container. This page uses the density you give it and does not model temperature or pressure.
Why is kg/L not offered as a unit?
Because it prints the same number as g/cm³: one kilogram per litre is one gram per cubic centimetre, which is 1000 kg/m³. Listing both would show one value twice, so the density units are g/cm³, kg/m³ and lb/ft³ only. Tonnes per cubic metre is left out for the same reason.
Why is a zero refused?
A sample with no mass has no density to report: the quotient would be 0, and a density of 0 would make the mass ÷ density division in the other direction impossible. A volume of zero is the same problem the other way round. The field names the reason instead of printing an infinite figure.
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