Density Calculator

How to use this calculator

For an unknown material, weigh it and measure its volume, then enter both. For irregular objects, measure volume by water displacement: the rise in a measuring cylinder (in mL) equals the object's volume in cm³. To find how much a known material weighs, enter its density and the volume; to find what volume a mass occupies, enter density and mass.

Unit menus include grams per cubic centimeter (common in labs), kilograms per cubic meter (SI), and pounds per cubic foot or per US gallon (common in engineering and shipping). The table below lists a few reference densities you can type straight in.

The formula

ρ = m / V

ρ: density
m: mass
V: volume

Worked example

A small cube with 1 cm sides weighs 19.3 g. What is its density — and could it be gold?

ρ = m / V = 19.3 g / 1 cm³ = 19.3 g/cm³.
In SI units: 19.3 g/cm³ × 1,000 = 19,300 kg/m³.

That matches pure gold (19.3 g/cm³). Lead, at 11.3 g/cm³, would weigh only 11.3 g for the same cube.

Reference densities

Material (≈20 °C)	g/cm³	lb/ft³
Fresh water	0.998	62.3
Seawater	1.025	64.0
Aluminum	2.70	169
Steel	7.85	490
Copper	8.96	559
Lead	11.34	708
Gold	19.32	1,206

Assumptions and limits

The sample is uniform; porous or composite objects give an average (bulk) density.
Density of liquids and gases depends on temperature and pressure; reference values are for room conditions.

Frequently asked questions

What is the density of water?

About 1.000 g/cm³ at 4 °C and 0.998 g/cm³ at 20 °C. That is 1,000 kg/m³, 62.4 lb/ft³ or 8.34 lb per US gallon.

What is the difference between density and specific gravity?

Specific gravity is density divided by the density of water, so it has no unit. A material with 2.7 g/cm³ has a specific gravity of 2.7.

Why does ice float?

Ice has a density of about 0.917 g/cm³, lower than liquid water, because its crystal structure holds molecules farther apart.