Density Calculator
Find density from mass and volume.
Results update as you type.
How it works
Density is a core property of matter that tells you how tightly mass is packed into a volume, and this density calculator returns it instantly from the mass and volume you enter. It reports the answer in kilograms per cubic metre and also converts to grams per cubic centimetre, the unit chemists and students most often use. A dense material like lead crams a lot of mass into a small space, while a light material like cork spreads little mass across a larger volume. Density matters because it predicts behaviour without weighing an entire object: whether something floats or sinks, which of two liquids layers on top, and what a metal is likely made of. Buoyancy, ship design, and even blood-test interpretation all hinge on comparing densities, so a quick density calculator saves time in the lab and the workshop alike. The formula works because density is simply mass divided by volume, an intrinsic ratio that stays the same whether you measure a gram or a tonne of the substance. Engineers, geologists, jewellers, and physics students all rely on a density calculator to identify materials, check purity, and solve textbook problems with confidence.
ρ = mass ÷ volume
Density measures how much mass is packed into a given volume, so dividing mass by volume gives the amount of matter per unit space. The formula works because mass and volume are both extensive properties that scale together for a uniform substance, leaving their ratio constant. That ratio is an intensive property, unique to each material regardless of how much of it you have, which is why it identifies substances so reliably.
Source:Standard physics (density)
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter mass and volume.
- 2
Adjust the options
Fine-tune any options to match your situation.
- 3
Read your result
Density updates instantly as you type — no button to press.
Frequently asked questions
What units should I use for mass and volume?
Enter mass in kilograms and volume in cubic metres to get density directly in kilograms per cubic metre. The calculator also converts that result to grams per cubic centimetre for convenience. If your measurements are in grams and cubic centimetres, you can convert first, but keeping to the labelled SI units guarantees both output figures are correct without any extra scaling on your part.
Why does the calculator show both kg/m³ and g/cm³?
Different fields prefer different units. Engineers and physicists usually work in kilograms per cubic metre, the SI standard, while chemists and students commonly quote grams per cubic centimetre because water conveniently sits at about 1 g/cm³. Showing both lets you compare your result against reference tables no matter which convention they use. The conversion factor is 1,000: one g/cm³ equals 1,000 kg/m³.
How does density predict whether something floats?
An object floats in a fluid if its density is lower than the fluid's density, and sinks if it is higher. Water has a density near 1,000 kg/m³, so any material below that, like wood or ice, floats, while denser materials like iron sink. This is why comparing an object's density to water is such a quick, reliable buoyancy check without any complex force diagrams.
Does temperature change a material's density?
Yes. Most substances expand when heated, spreading the same mass over a larger volume, which lowers density. This is why warm air rises and why liquids stratify by temperature. Water is a famous exception, reaching maximum density near 4°C before expanding as it freezes. For precise work, always note the temperature at which a reference density was measured and match your conditions to it.
Can I use this to identify an unknown material?
Often, yes. Measure the object's mass and volume, compute its density here, and compare the figure against a table of known material densities. A close match strongly suggests the material's identity, since density is an intensive property unique to each substance. Be careful with alloys, porous samples, or trapped air, which can shift the reading, and confirm with a second property when precision matters.