A 1,000 g sample occupying 200 cm³
ρ = m ÷ V
Divide 1,000 by 200 to get 5 g/cm³. In SI units, 1 kg ÷ 0.0002 m³ = 5,000 kg/m³. This is an illustrative sample, not a material identification.
Mass & volume
Density Calculator
Calculate density, mass, or volume from the other two quantities, with metric and customary unit conversion.
Calculate density, mass, or volume
Density
Enter two positive quantities, then select Calculate.
- SI equivalent
- Formula
Calculation steps
≈ marks display rounding. Calculations run in your browser. Press Enter to calculate. Successful results appear in this tab's Recent calculations.
Three ways to use the density formula
2 L at a density of 0.8 g/mL
m = ρ × V
2 L is 2,000 mL. Multiplying 0.8 g/mL by 2,000 mL gives 1,600 g, or 1.6 kg.
12 lb at a density of 3 lb/ft³
V = m ÷ ρ
The mass units cancel: 12 lb ÷ (3 lb/ft³) = 4 ft³. The SI volume is exactly 0.113267386368 m³ before display rounding.
Units, measurement limits, and rounding
Mass density ρ is mass per volume. The SI unit is kg/m³. For a nonuniform sample, total mass divided by total volume gives its average density. It does not reveal the density at every point within the sample.
The mass options use the international avoirdupois pound: 1 lb = 0.45359237 kg exactly, and 1 oz = 1/16 lb. These are mass units, not pound-force or fluid ounces. Cubic feet and cubic inches use the international definitions 1 ft = 0.3048 m and 1 in = 0.0254 m, cubed before conversion. A litre is 0.001 m³; a millilitre and a cubic centimetre both equal 0.000001 m³.
1 g/cm³, 1 g/mL, and 1 kg/L all equal 1,000 kg/m³. The customary density conversions are derived from the exact mass and cubic-length definitions, rather than from a shortened decimal conversion factor.
All active inputs must be positive, with at most 64 characters, 15 integer digits, and 10 decimal places. Numeric fields do not accept expressions, scientific notation, or embedded units. An inactive field does not affect the answer.
The calculation preserves exact fractions through unit conversion and arithmetic. Only the final decimal display is rounded; halfway values round away from zero. Trailing zeros are omitted. ≈ indicates a rounded value, and a notice appears if a positive result rounds to zero. Changing the result unit or display precision does not add a recent-calculation entry.
A density measurement depends on the sample and its conditions. This tool does not look up materials, model thermal expansion, estimate porosity, propagate measurement uncertainty, or calculate specific gravity. More displayed digits do not make an input measurement more accurate.
References: OpenStax — measurements and density and NIST Guide to the SI — exact unit definitions.
Common questions
Is density the same as weight?
No. Mass describes the amount of matter, while weight is a force that depends on gravity. Density is mass divided by volume. This tool uses kilograms, grams, pounds, and ounces as mass units; it does not calculate weight force.
Why are g/cm³ and g/mL equivalent?
A cubic centimetre and a millilitre have exactly the same volume. Dividing the same mass by either gives the same number. For example, 2 g/cm³ equals 2 g/mL and 2,000 kg/m³.
Can I use a material's density from a table?
Yes, if that value describes your material and measurement conditions. For a powder, the bulk volume may include spaces between particles, so its bulk density differs from the density of the solid material itself. This calculator uses the value you provide without choosing between those definitions.
Why must mass, volume, and density be positive?
This tool models a positive amount of material occupying a positive volume. A zero volume makes mass divided by volume undefined, and some zero-value combinations do not determine a unique missing quantity. Zero and negative inputs are excluded from all three modes.
Does a result marked ≈ 0 mean the sample has no mass or density?
No. A positive answer can round to zero at the chosen display precision. Choose a smaller result unit or more decimal places. The unrounded value is still used when changing the result unit.