Volume to Mass Calculator

Enter a volume and a density — or pick a common material — to find mass using m = ρ × V, with results in kilograms, grams, pounds, and ounces.

Quick Facts

Core formula
m = ρ × V
Mass equals density times volume, once both are converted to matching units.
Water reference
1 L of water ≈ 1 kg
Water's density is close to 1000 kg/m³ (1 g/cm³) near room temperature.
Density unit conversion
1 g/cm³ = 1000 kg/m³ = 62.43 lb/ft³
Handy for converting between metric and imperial density tables.

Your Results

Calculated
Mass
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m = ρ × V, in kilograms
Mass (grams)
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Mass converted to grams
Mass (pounds)
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Mass converted to pounds (avoirdupois)
Mass (ounces)
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Mass converted to ounces (avoirdupois)

Ready

Enter a volume and density (or pick a material), then press Calculate.

How to Convert Volume to Mass

Volume and mass are linked by density, the amount of matter packed into a given space. The relationship is m = ρ × V, where m is mass, ρ (rho) is density, and V is volume. This calculator converts your volume to cubic meters and your density to kilograms per cubic meter behind the scenes, multiplies them to get mass in kilograms, then reports that mass in grams, pounds, and ounces as well.

The volume-to-mass formula

Density is defined as mass per unit volume: ρ = m / V. Rearranging for mass gives the formula this calculator uses: m = ρ × V. Because volume can be measured in liters, cubic feet, gallons, or cubic meters, and density can be tabulated in kg/m³, g/cm³, g/L, or lb/ft³, the two values must be converted to compatible units before multiplying — this calculator handles that conversion automatically so you can mix units freely (for example, a volume in gallons with a density in g/cm³).

Choosing an accurate density value

  • Use the density of the actual material, not a guess. Density varies enormously between substances — water is about 1000 kg/m³, aluminum is about 2700 kg/m³, and gold is about 19,300 kg/m³ — so a small error in density produces a proportional error in mass.
  • Account for temperature and pressure. Liquids and especially gases change density noticeably with temperature and pressure. Water's density peaks at about 1000 kg/m³ near 4°C and decreases slightly as it warms; air at sea level is roughly 1.225 kg/m³ but thins out at altitude or when heated.
  • Watch for hollow or mixed objects. This calculator assumes a uniform, solid material. A hollow sphere or a composite object (like a filled container) has a lower effective density than the solid material it's made from, so measure the object's actual mass-to-volume ratio when possible rather than looking up a single material's density.

Frequently Asked Questions

What is the formula for converting volume to mass?
Mass equals density times volume: m = ρ × V. For example, 2 liters (0.002 m³) of water at a density of 1000 kg/m³ has a mass of 0.002 × 1000 = 2 kg.
How much does a liter of water weigh?
About 1 kilogram. Water's density is very close to 1000 kg/m³ (1 g/cm³) near room temperature, so 1 liter of water has a mass of approximately 1 kg (about 2.2 lb).
Why do equal volumes of different materials have different masses?
Because mass depends on both volume and density, and density varies by material. A liter of gold (about 19.3 kg) is far heavier than a liter of water (about 1 kg) or a liter of air (about 1.2 grams) because gold atoms are packed more densely.
Does temperature or pressure change the volume-to-mass conversion?
Yes. Density depends on temperature and, for gases, pressure — most materials expand slightly and become less dense as they warm up. For precise work, use a density value measured at the temperature and pressure relevant to your calculation rather than a generic textbook figure.

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