Density Calculator

Find the density of an object from its mass and volume — or the mass or volume from the density. Includes common materials and whether the object floats in water.

MatterMaterialsBuoyancy

Inputs

Input examples

Click Solve next to the quantity you want to find: it moves into the result below. Then fill in the other two. Pick a material to fill in its density.

Material

Mass m

Volume V

Density ρ

What is Density?

Density tells you how much mass is packed into a given volume. A kilogram of feathers and a kilogram of lead weigh the same, but the lead takes up far less space: it is much denser.

Whether something floats depends only on density: an object less dense than the liquid around it floats, a denser one sinks. That is why ice floats on water and a steel ship floats only because its hull encloses lots of air.

ρ < 1 g/cm³floats in water

ρ > 1 g/cm³sinks in water

1 g/cm³= 1000 kg/m³

1 L waterweighs 1 kg

Density Comparison

log scale

Result

Enter the values above

Densities of Materials

at about 20 °C

Material	kg/m³	g/cm³
Air (sea level)	1.20	0.0012
Cork	240	0.24
Pine wood	~500–700	0.5–0.7
Ice	917	0.917
Water	998	1.00
Seawater	1025	1.03
Aluminium	2700	2.70
Iron / steel	7870	7.87
Lead	11 340	11.34
Mercury	13 534	13.53
Gold	19 300	19.30

Worked Techniques

Volume by Water Displacement

For an irregular object, lower it into a measuring cylinder: the rise in water level is its volume. Archimedes is said to have checked a crown this way.

Example: water rises from 300 to 500 mL → V = 200 cm³.

Identifying a Material

Density is a property of the material, not the object. Compare your result with the table to see what it is probably made of.

Example: 2.7 g/cm³ matches aluminium.

Floating Fraction

A floating object sinks until it displaces its own weight of liquid. That is why about 90% of an iceberg is under water.

Example:

Sources & Verification

References

D. Halliday, R. Resnick & J. Walker, Fundamentals of Physics, 10th ed., Wiley, 2014 — Ch. 14 (Fluids).