⚗️ Density Calculator
Calculate density, mass, or volume using the fundamental formula D = M / V. Select what you want to find, enter the other two values with your preferred units, and get instant results in multiple unit systems.
The Density Formula
Where D = Density (kg/m³), M = Mass (kg), V = Volume (m³). The SI unit of density is kg/m³; g/cm³ is also widely used (1 g/cm³ = 1000 kg/m³).
Worked Example — Density of Aluminium Block
Frequently Asked Questions
Density is the amount of mass contained in a unit volume of a substance. It is expressed as D = M/V where D is density, M is mass, and V is volume. Denser materials pack more mass into the same space — for example steel (7850 kg/m³) is much denser than wood (~600 kg/m³).
The SI unit of density is kilograms per cubic metre (kg/m³). Other common units include grams per cubic centimetre (g/cm³), grams per litre (g/L), and pounds per cubic foot (lb/ft³). To convert: 1 g/cm³ = 1000 kg/m³ = 1 kg/L.
Pure water at 4°C has a density of exactly 1000 kg/m³ (or 1 g/cm³). This is used as a reference point — materials with density greater than 1 g/cm³ sink in water, while those less than 1 g/cm³ float.
Use the water displacement method: submerge the object in a measuring cylinder of water and record the rise in water level. The volume of water displaced equals the volume of the object. This is the principle Archimedes discovered.
Relative density (specific gravity) is the ratio of a substance's density to the density of water (1000 kg/m³). It is dimensionless. For example, steel has a specific gravity of 7.85, meaning it is 7.85 times denser than water.
Related Calculators
Steel Weight Calculator
Calculate the weight of steel bars, plates, pipes, and sections by dimensions.
Concrete Calculator
Estimate concrete volume and bags needed for slabs, footings, columns, and walls.
Pressure Calculator
Calculate pressure from force and area, or convert between pressure units.