What is the formula for density?

Density (ρ) equals mass (m) divided by volume (V): ρ = m ÷ V. Rearranged: m = ρ × V and V = m ÷ ρ.

What is the SI unit of density?

The SI unit is kilograms per cubic meter (kg/m³). In chemistry, grams per cubic centimeter (g/cm³) is equally common and numerically equivalent to g/mL.

What is specific gravity?

Specific gravity is the ratio of a substance's density to the density of water (1.0 g/cm³ at 4 °C). It is dimensionless and numerically equal to density in g/cm³.

Why does gold sink but wood floats?

Gold has a density of about 19.3 g/cm³ — far denser than water — so it sinks. Pine wood is about 0.51 g/cm³, less than water, so it floats. Objects with density below 1.0 g/cm³ float in water.

Density Calculator

Name: Density Calculator
Availability: InStock
Author: Nham Vu

Enter any two of mass, volume, or density — in your chosen units — and instantly compute the third. Cross-conversions and a material reference table included.

Density Calculator

Find:

Mass

Volume

Enter two known values on the left and click Calculate.

Density

—

g/cm³

All Units

Common Material Densities

Material	g/cm³	kg/m³	lb/ft³

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Summary

Enter any two of mass, volume, or density — in your chosen units — and instantly compute the third. Cross-conversions and a material reference table included.

How it works

Select the quantity you want to find: Mass, Volume, or Density.
Enter values for the other two quantities and choose their units.
Click Calculate to instantly compute the result.
View cross-conversions of the result in all supported units.
Scroll the reference table to look up densities of common materials.

Use cases

Determine the mass of a liquid given its volume and density.
Find the volume of a metal block from its weight and known density.
Verify whether an unknown substance matches a reference material.
Convert between different density units for scientific calculations.

Frequently Asked Questions

Last updated: 2026-06-09 · Reviewed by Nham Vu