Mass to Density Calculator

Enter a mass and a volume to calculate density using ρ = m / V, with automatic conversion across metric and imperial mass and volume units, plus specific gravity relative to water.

Quick Facts

Formula
ρ = m / V
Density equals mass divided by volume — the defining relationship for density.
Water density
1,000 kg/m³
Equal to 1 g/cm³ or 1 kg/L at 4°C — the reference point for specific gravity.
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 density against real materials.

Your Results

Calculated
Density (kg/m³)
-
ρ = m / V, in kg/m³
Density (g/cm³)
-
kg/m³ ÷ 1,000
Density (lb/ft³)
-
kg/m³ ÷ 16.0185
Specific Gravity
-
Density ÷ 1,000 kg/m³ (water)

Ready

Enter a mass and volume, then press Calculate.

About the Mass to Density Calculator

Density describes how much matter is packed into a given space: ρ = m / V, where ρ (rho) is density, m is mass, and V is volume. This calculator converts your inputs to consistent base units first, so you can mix and match mass units (grams, kilograms, milligrams, pounds, ounces) with volume units (cubic centimeters, liters, cubic meters, cubic feet, cubic inches, US gallons, cubic yards) and still get a correct density in kg/m³, g/cm³, lb/ft³, and specific gravity.

How the calculation works

The calculator first converts your mass value to kilograms and your volume value to cubic meters (m³), then divides mass by volume to get density in kilograms per cubic meter: ρ = m / V. That kg/m³ figure is then converted into grams per cubic centimeter (÷ 1,000), pounds per cubic foot (÷ 16.0185), and specific gravity (÷ 1,000, the density of water). Converting both inputs to shared base units before dividing is what keeps the result correct no matter which combination of units you pick — dividing a gram mass directly by a cubic-foot volume without conversion would be off by a large factor.

Getting accurate results

  • Weigh and measure under matching conditions: density changes with temperature and pressure, so take the mass and volume measurements close together in time and at the conditions you care about, especially for liquids and gases.
  • Double-check unit selections: a gram-per-cubic-centimeter result and a kilogram-per-liter result are numerically identical, but pounds and ounces mixed with the wrong volume unit can throw off the answer by orders of magnitude.
  • 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 your result's specific gravity to these benchmarks.

Frequently Asked Questions

What is the formula for calculating density from mass and volume?
Density equals mass divided by volume: ρ = m / V. For example, a block with a mass of 1,350 g and a volume of 500 cm³ has a density of 1,350 / 500 = 2.7 g/cm³, which is the density of aluminum.
What is specific gravity and how does it relate to density?
Specific gravity is the ratio of a material's density to the density of water (1,000 kg/m³, or 1 g/cm³, at 4°C). A specific gravity greater than 1 means the material sinks in water; less than 1 means it floats. It is dimensionless, so it has the same value in every unit system.
How do I convert a density result from kg/m³ to g/cm³?
Divide by 1,000: 1,000 kg/m³ = 1 g/cm³. This follows because 1 m³ = 1,000,000 cm³ and 1 kg = 1,000 g, so the two factors combine into a simple division by 1,000.
Does temperature or pressure change a measured density?
Yes. Most materials expand and become less dense when heated and contract when cooled, and gases are especially sensitive to both temperature and pressure. Measure the mass and volume under the conditions you care about, since ρ = m / V only reports the density at those specific conditions.

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