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Density Calculator

Calculate density, mass, or volume instantly with full unit conversion and material comparison

Updated

What is the Density Calculator?

Use the density formula ρ = m / V to calculate density, mass, or volume. Choose from the supported mass, volume, and density units; the calculator converts values between them.

The tool can compare a calculated density with values in a built-in material reference list. A close match does not identify an unknown sample, since density varies with composition, temperature, and measurement conditions. The float/sink result is a simplified comparison with fresh water and does not account for an object's shape or displacement.

Results are mathematical estimates based on the values and units you enter; measurement accuracy depends on your inputs.

How it works

  1. Choose what you want to solve for. Pick Density, Mass, or Volume depending on which value is unknown. The calculator automatically shows the two input fields needed for that calculation.

  2. Enter your known values. Type in the numbers and select the matching units from the dropdowns. Mass supports units from milligrams to tonnes; volume supports everything from cubic millimetres to gallons.

  3. Read the result instantly. The calculator applies the density formula:

ρ=mV\rho = \frac{m}{V}

where ρ is density, m is mass, and V is volume. Rearranged forms are used automatically when solving for mass (m = ρV) or volume (V = m / ρ).

  1. Compare across units. Your result is shown simultaneously in kg/m³, g/cm³, kg/L, and lb/ft³, so you don't need to run a separate conversion.

  2. Compare reference values. The calculator lists materials in its reference table with densities closest to your result. This can provide context, but it cannot identify an unknown sample.

  3. Compare with fresh water. A simple indicator compares the entered density with a reference value for fresh water. Actual floating depends on the object's average density, shape, and the fluid's conditions.

Calculations run in your browser.

Examples

Find the density of a gold sample

Calculate a sample's density from its measured mass and volume, then compare it with reference values.

Mass: 500 g, Volume: 25.9 cm³
 
Density: approximately 19.31 g/cm³ (near a typical gold reference value)

Find the mass of a known volume of water

Solve for mass when density and volume are known

Density: 1000 kg/m³, Volume: 2 L
 
Mass: 2 kg

Find the volume of a steel block

Solve for volume when density and mass are known

Density: 7850 kg/m³, Mass: 15.7 kg
 
Volume: 2 L (2000 cm³)

Frequently asked questions

What is the formula for density?

Density is calculated as ρ = m / V, where mass (m) is divided by volume (V). The result is typically expressed in kilograms per cubic metre (kg/m³) or grams per cubic centimetre (g/cm³).

How do I find mass or volume instead of density?

Switch the calculator's mode to "Solve for Mass" or "Solve for Volume." The formula is rearranged automatically: mass is found with m = ρV, and volume is found with V = m / ρ.

What units does this density calculator support?

Mass units include milligrams, grams, kilograms, tonnes, ounces, pounds, stone, and both US and UK tons. Volume units include millilitres, litres, cubic metres, cubic inches, cubic feet, and US/UK gallons, quarts, pints, and cups. Density results are shown in kg/m³, g/cm³, kg/L, and lb/ft³.

How do I know if an object will float or sink?

An object's average density compared with the surrounding fluid is one factor in whether it floats. Shape, trapped air, and fluid conditions also matter. This calculator only compares the entered density with a fresh-water reference value.

Why is my calculated density slightly different from a textbook value?

Differences can come from measurement precision, temperature, composition, or impurities. Reference densities are approximate values under specified conditions.

What's the difference between density and specific gravity?

Specific gravity is the ratio of a substance's density to the density of water (or air, for gases), so it has no units. Density itself is always expressed in mass-per-volume units like kg/m³ or g/cm³.

Can I use this calculator for gases and liquids, not just solids?

Yes. The density formula applies to any state of matter. Just make sure your volume measurement accounts for the full space the substance occupies, since gases and liquids take the shape of their container.

Is my data stored when I use this calculator?

Calculations happen in your browser; the tool does not need to send values to a calculation service.

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