Density Calculator
Calculate density, mass or volume knowing two of the three values (ρ = m/V).
Tip: The density of water (1 g/cm³ = 1,000 kg/m³) serves as a reference point — materials with density > 1 g/cm³ sink in water.
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About this digital tool
The density calculator finds the density (ρ), mass (m) or volume (V) of a material from two of them. Choose what you are looking for, choose the units (kg/m³ or g/cm³), enter the two known values and get the result. You can compare with the densities of water, iron, air and concrete.
The formula is ρ = m ÷ V, from which m = ρ × V and V = m ÷ ρ. For example, 600 kg in 0.5 m³ gives a density of 600 ÷ 0.5 = 1200 kg/m³. Water has a density of about 1000 kg/m³, so anything lower than this means the material floats. It is used in physics, chemistry, construction, engineering and in choosing materials.
How to use
- Choose what you want to find (ρ, m, or V)
- Enter the two known values
- Choose the units (kg/m³, g/cm³, g/mL)
- See the result
- Compare with the reference densities of materials
Frequently asked questions
What is the formula for density?
ρ = m/V (density = mass ÷ volume). SI unit: kg/m³. Other common units: g/cm³, g/mL, kg/L. 1 g/cm³ = 1,000 kg/m³.
How do I measure density in practice?
Measure the mass with a scale, measure the volume by geometry (cubes/cylinders) or by immersion in water (Archimedes' method). Density = mass/volume.
Why is density important?
It determines whether objects float or sink, helps identify materials (each material has a unique density), and is used in structural engineering, quality control, etc.
How do I find the mass when I know the density and the volume?
m = ρ × V. E.g. water (1000 kg/m³) in 0.25 m³ has a mass of 1000 × 0.25 = 250 kg. Choose "Mass" under "What are you looking for?".