Density Calculator
Find density in kg/m³, g/cm³ and lb/ft³ from mass and volume, with specific gravity vs water.
Density
800 kg/m³
Equivalent to 0.8 g/cm³
In lb/ft³
49.94 lb/ft³
Specific gravity
0.8
Reference
Water is 1 g/cm³
Specific gravity compares your material to water
Density = mass ÷ volume. Pure water is 1,000 kg/m³; steel is about 7,850 kg/m³; concrete is around 2,400 kg/m³.
Density Calculator on True Calculator gives you an instant, accurate answer with no sign-up and no app install. Find density in kg/m³, g/cm³ and lb/ft³ from mass and volume, with specific gravity vs water. Every result shows the formula and a worked example so you can verify the calculation yourself, and all values are computed in your own browser — your numbers never leave your device.
Popular uses: density calculator · mass volume density · specific gravity calculator
How We Calculate
This calculator uses standard physics and chemistry formulas verified by our team. All calculations are performed instantly in your browser using JavaScript — no data is sent to any server.
Formulas follow standard scientific definitions and physical constants, consistent with what is taught in school and university courses.
When to Use This Calculator
Use this calculator in any situation that pairs mass with volume: checking whether a metal is genuine, working out if a wooden plank will float, computing the weight of a water tank, or verifying the density of concrete cubes in a lab. Students and engineers across India use density to convert between weight and volume when ordering sand, aggregates and soil, since suppliers sell by volume but trucks are limited by weight. The specific gravity readout is useful for battery acid, coolant and sediment testing, and in quality-control labs it is the fastest way to spot a diluted or adulterated sample. For furniture movers, knowing density helps estimate whether a solid stone top is too heavy for a floor — the numbers speak before the labourers do.
How to Use This Calculator
- Step 1: Weigh the object or sample and enter its mass in kilograms.
- Step 2: Measure the volume — for a regular block multiply length × width × height; for liquids use a measuring cylinder.
- Step 3: Enter the volume in cubic metres (1 litre = 0.001 m³).
- Step 4: Read the density in kg/m³, g/cm³ and lb/ft³, plus the specific gravity against water.
Worked Example
A concrete block weighing 240 kg with a volume of 0.1 m³ has a density of 2,400 kg/m³. That equals 2.4 g/cm³, and its specific gravity is 2.4 — 2.4 times heavier than the same volume of water. In imperial units the same material measures 149.83 lb/ft³. Because the density is above 1 g/cm³, the block sinks in water, as anyone who has tried to float one knows.
Tips and Common Mistakes
- •For irregular objects, measure volume by water displacement in a calibrated container.
- •Dry porous samples like bricks or wood before weighing, or moisture inflates the density.
- •Check temperature: water at 4 °C is 1,000 kg/m³ but less dense when hot or frozen.
- ✗Do not mix units — mass in kg with volume in litres gives a misleading figure (divide litres by 1,000).
- ✗Do not treat table densities as exact; moisture and impurities shift every real-world material.
Frequently Asked Questions
How is density calculated?
Density = mass ÷ volume. A 120 kg block occupying 0.15 m³ has a density of 800 kg/m³, or 0.8 g/cm³. The same quantity can be expressed in any mass-per-volume unit.
What is specific gravity?
Specific gravity is the density of a material divided by the density of water (1 g/cm³). A density of 0.8 g/cm³ therefore means specific gravity 0.8 — the material floats; values above 1 sink.
How do I convert kg/m³ to g/cm³?
Divide by 1,000. Water is 1,000 kg/m³ = 1 g/cm³; steel is about 7,850 kg/m³ = 7.85 g/cm³. This calculator shows both units automatically.
What are common material densities?
Water 1,000 kg/m³, concrete about 2,400 kg/m³, mild steel 7,850 kg/m³, aluminium 2,700 kg/m³, and air about 1.2 kg/m³ at sea level. Density varies slightly with temperature and moisture.
Why might my measured density differ from tables?
Purity, temperature, trapped air and moisture all change density. For porous or damp materials, dry the sample first or use the apparent volume including pores, depending on what you need the density for.
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