What density tells you about an object
Density describes how tightly mass is packed into a given volume. Two objects can be the same size and look identical, but if one is much heavier, it has a higher density — this is why a solid steel ball sinks in water while a same-sized foam ball floats. Density is one of the most basic ways to identify or compare materials, since every substance has a roughly consistent, well-documented density under normal conditions.
This calculator solves the density equation in any direction: find density from mass and volume, find mass from density and volume, or find volume from mass and density — pick the mode that matches what you actually know.
How to Calculate Density, Mass, or Volume (step by step)
Solving for density, given mass and volume
density = mass ÷ volume
For the defaults (500 g, 200 cm³):
500 ÷ 200 = 2.5 g/cm³
Solving for mass, given density and volume
mass = density × volume
For a density of 2.5 g/cm³ and a volume of 200 cm³:
2.5 × 200 = 500 g
Solving for volume, given mass and density
volume = mass ÷ density
For a mass of 500 g and a density of 2.5 g/cm³:
500 ÷ 2.5 = 200 cm³
Working across different units
Whichever mode you use, every value is first converted to a common base (grams for mass, cubic centimeters for volume) before the calculation runs, then the result is converted to whichever unit you’ve selected. That’s what lets you freely mix units — solving for mass with density in kg/m³ and volume in cubic feet works exactly the same as using grams and cm³ throughout.
Common material densities
A few reference points, in g/cm³: water is 1.0, aluminum is 2.7, iron is 7.86, steel is about 8.05, and copper is 8.96. Comparing a measured or calculated density against known values like these is a common way to identify an unknown material.