Density is the mass per unit volume of a substance, typically expressed in g/cm³ or kg/m³. It is an intensive property - it does not depend on the amount of substance. Water has a density of 1 g/cm³; iron is about 7.87 g/cm³; gold is 19.3 g/cm³.

Why do objects float or sink?

An object floats if its density is less than the density of the fluid it is placed in (Archimedes' principle). A steel ship floats because its overall density (including the air inside) is less than water. A solid steel ball sinks because its density (7.87 g/cm³) exceeds water's (1 g/cm³).

What is the density of water?

Pure water at 4°C has a density of exactly 1.000 g/cm³ (or 1000 kg/m³). This is the temperature at which water is densest. At 100°C, water's density drops to about 0.958 g/cm³. Saltwater is denser than freshwater (about 1.025 g/cm³ for seawater).

How is density used in chemistry?

Density is used to identify unknown substances (each pure substance has a characteristic density), convert between mass and volume measurements, calculate concentrations of solutions, and understand phase behavior. It is also used in quality control to verify material purity.

What is relative density (specific gravity)?

Relative density (or specific gravity) is the ratio of a substance's density to the density of a reference substance (usually water at 4°C). It is dimensionless. A specific gravity of 2.5 means the substance is 2.5 times denser than water. It is used in geology, brewing, and petroleum industries.

Science

Density Calculator

Calculate density, mass, or volume using the fundamental density formula. Includes a reference table of common material densities.

✏️

Enter Values

Solve For

First Known Value*

Unit

Second Known Value*

Unit

📊

Results

Enter values above to see results

ρ = m / V | m = ρ × V | V = m / ρ

Variables

ρDensity (Greek letter rho)

mMass

VVolume

Explanation

Density is a fundamental physical property that describes how much mass is packed into a given volume. It determines whether objects float or sink (objects less dense than water float), and is crucial in materials science, chemistry, and engineering.

What is the Density Calculator?

Density is one of the most fundamental physical properties of matter. It determines whether objects float or sink, how materials behave under pressure, and how substances can be identified. From engineering design to chemistry experiments to everyday curiosity about why some things float, density calculations are essential across many fields.

How to Use This Calculator

Select two known quantities (any combination of density, mass, and volume), enter their values with appropriate units, and the calculator solves for the third. Results are provided in multiple unit systems for convenience.

Worked Examples

A 500 g object with a volume of 250 cm³

Weighing an object and measuring its volume by water displacement.

Density = mass ÷ volume: 500 ÷ 250 = 2.0 g/cm³
In SI units: 2,000 kg/m³

Density 2.0 g/cm³ — twice as dense as water, so it sinks.

Anything above 1 g/cm³ sinks in fresh water; below it floats.

Identifying a metal sample

A 787 g metal block that displaces 100 cm³ of water.

Density = 787 ÷ 100: 7.87 g/cm³

Density 7.87 g/cm³ — that matches iron.

Each pure material has a characteristic density, so this is a quick way to identify an unknown sample.

Why Use MyCalculatorsHub's Density Calculator?

This calculator supports a comprehensive range of units for mass (grams, kilograms, pounds), volume (cm³, mL, liters, m³), and density (g/cm³, kg/m³), making it suitable for both scientific and everyday applications.

Common Mistakes to Avoid

A common mistake is confusing mass and weight. Mass is the amount of matter (measured in kg or g); weight is the gravitational force on that mass (measured in Newtons). For density calculations, always use mass, not weight. Also, ensure volume and mass units are compatible (both metric or both imperial).