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Mass Calculator

Calculate mass from density and volume (m = ρ × V). Supports multiple units with conversions and common material presets.

Mass
2,625 kg
m = ρ × V = 7500 kg/m³ × 0.35 m3
UnitValue
kilogram [kg]2,625
gram [g]2,625,000
milligram [mg]2.625000e+9
pound [lb]5,787.14
ounce [oz]92,594.2
metric ton [t]2.625

The Mass Formula

Mass is calculated using the density formula rearranged to solve for mass:

m = ρ × V

Where m is mass, ρ (rho) is density, and V is volume. This is one of three rearrangements of the density equation:

  • Find mass: m = ρ × V
  • Find density: ρ = m / V
  • Find volume: V = m / ρ

Mass vs Weight

PropertyMassWeight
DefinitionAmount of matterGravitational force on matter
SI Unitkilogram (kg)newton (N)
Changes with location?NoYes (depends on gravity)
On the MoonSame as Earth~1/6 of Earth weight
In zero gravitySame as EarthZero
Measured withBalance scaleSpring scale

Common Material Densities

MaterialDensity (kg/m³)1 m³ mass (kg)
Air (20°C)1.21.2
Wood (oak)750750
Water1,0001,000
Concrete2,4002,400
Aluminum2,7002,700
Steel7,8507,850
Copper8,9608,960
Gold19,32019,320

Practical Examples

  • Shipping: A crate 1.2 m × 0.8 m × 0.6 m filled with water weighs 1,000 × 0.576 = 576 kg
  • Construction: A concrete slab 3 m × 2 m × 0.15 m weighs 2,400 × 0.9 = 2,160 kg
  • Cooking: 500 mL of olive oil weighs 911 × 0.0005 = 0.456 kg (456 g)
  • Metalwork: A steel rod 2 m long, 5 cm diameter weighs 7,850 × 0.00393 = 30.8 kg

Unit Conversion Reference

FromTo kg
1 gram (g)0.001 kg
1 milligram (mg)0.000001 kg
1 pound (lb)0.4536 kg
1 ounce (oz)0.02835 kg
1 metric ton (t)1,000 kg

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Frequently Asked Questions

How is mass calculated from density and volume?

Mass equals density multiplied by volume: m = ρ × V. Enter the density of the material and the volume of the object, and the calculator converts units and computes mass in all common units.

What is the difference between mass and weight?

Mass is the amount of matter in an object (measured in kg or lb-mass). Weight is the force of gravity on that mass (measured in newtons or lb-force). On Earth, weight ≈ mass × 9.81 m/s². Mass stays the same everywhere; weight changes with gravity.

How do I find the density of a material?

Use the common materials list in the calculator, look up the material in a reference table, or measure it: weigh the object and divide by its volume. For irregular shapes, use water displacement to find volume.

What units does the calculator support?

Density: kg/m³, g/cm³, g/mL, kg/L, lb/ft³, lb/in³, lb/gal. Volume: m³, cm³, L, mL, ft³, in³, gal. Results are shown in kg, g, mg, lb, oz, and metric tons.

Why do I need to calculate mass?

Common uses include shipping (calculating freight weight), engineering (structural loads), cooking (scaling recipes by volume), science experiments, and material estimation for construction projects.

Can I use this for liquids?

Yes. Enter the liquid density (water ≈ 1,000 kg/m³, milk ≈ 1,030 kg/m³, gasoline ≈ 750 kg/m³) and the volume. The calculator computes the mass of that volume of liquid.