Density To Mass Calculator

Enter a density and a volume to calculate mass using m = ρ × V, with automatic conversion across metric and imperial density and volume units.

Quick Facts

Formula
m = ρ × V
Mass equals density multiplied by volume — a direct rearrangement of ρ = m / V.
Water density
1,000 kg/m³
Equal to 1 g/cm³ or 1 kg/L at 4°C — a handy reference point for sanity checks.
Unit shortcut
1 g/cm³ = 1,000 kg/m³ = 1 kg/L
The three most common metric density units are simple multiples of each other.
Typical densities
Aluminum ≈2,700 · Steel ≈7,850 kg/m³
Useful for sanity-checking a calculated mass against real materials.

Your Results

Calculated
Mass (kilograms)
-
m = ρ × V, in kg
Mass (grams)
-
Mass × 1,000
Mass (pounds)
-
Mass ÷ 0.45359237
Mass (ounces)
-
Pounds × 16

Ready

Enter a density and volume, then press Calculate.

About the Density To Mass Calculator

Density relates how much matter is packed into a given space: ρ = m / V, where ρ is density, m is mass, and V is volume. Rearranging that definition for mass gives m = ρ × V — multiply a substance's density by the volume you have, and the result is its mass. This calculator converts your inputs to consistent base units first, so you can mix and match density units (g/cm³, kg/m³, kg/L, lb/ft³, lb/in³, lb/gal) with volume units (liters, cubic meters, cubic centimeters, cubic feet, cubic inches, US gallons, cubic yards) and still get a correct mass in kilograms, grams, pounds, and ounces.

How the calculation works

The calculator first converts your density value to kilograms per cubic meter (kg/m³) and your volume value to cubic meters (m³), then multiplies the two together to get mass in kilograms: m = ρ × V. That kilogram figure is then converted into grams (× 1,000), pounds (÷ 0.45359237), and ounces (pounds × 16) for convenience. Converting both inputs to shared base units before multiplying is what keeps the result correct no matter which combination of units you pick — multiplying a g/cm³ density directly by a cubic-foot volume without conversion would be off by a factor of tens of thousands.

Getting accurate results

  • Match the density to real conditions: density changes with temperature and pressure, so use a value measured (or looked up) close to your material's actual conditions, especially for gases and liquids.
  • Double-check unit selections: g/cm³ and kg/L are numerically identical, and both equal 1,000 kg/m³ — but lb/ft³, lb/in³, and lb/gal are all different from one another, so pick the option that matches your source data.
  • Sanity-check against known materials: water is about 1,000 kg/m³ (1 g/cm³), aluminum about 2,700 kg/m³, steel about 7,850 kg/m³, and air at sea level about 1.2 kg/m³ — compare the implied density of your result to these benchmarks.

Frequently Asked Questions

What is the formula for calculating mass from density and volume?
Mass equals density multiplied by volume: m = ρ × V. This comes directly from the definition of density, ρ = m / V, solved for m. For example, 500 cm³ (0.5 L) of a material with a density of 2.7 g/cm³ (aluminum) has a mass of 2.7 × 500 = 1,350 g, or 1.35 kg.
How do I convert g/cm³ to kg/m³?
Multiply by 1,000: 1 g/cm³ = 1,000 kg/m³. This is because 1 cm³ = 10⁻⁶ m³ and 1 g = 10⁻³ kg, so the conversion factor works out to 1,000. The same factor applies between g/mL and kg/m³, and between g/cm³ and kg/L, which are numerically equal.
Why does the volume unit choice matter for the result?
Because mass scales linearly with volume, using the wrong volume unit (for example, cubic inches instead of cubic feet) can throw off the mass by orders of magnitude. Always confirm that the density and volume units you select actually match your measurements before trusting the result.
Does temperature or pressure affect this calculation?
Yes, indirectly. Density itself changes with temperature and pressure since most substances expand and become less dense when heated, so the density value you enter should reflect the actual conditions of your material. Once you have an accurate density figure, the m = ρ × V relationship itself does not change with conditions.

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