Density Calculator

Name: Density Calculator
Author: True Calculator automated test suite

Find density in kg/m³, g/cm³ and lb/ft³ from mass and volume, with specific gravity vs water.

Mass

Volume

m³

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.

Last updated: January 2026

How this calculator is verified

Checked by True Calculator automated test suite on 23 August 2026

Formula verified against a published worked example in the automated test suite
Edge cases (zero, negative, boundary and unit-mismatch inputs) covered by unit tests

The full verification method is on our how we verify page. Found an error? Tell us and we will re-check it.

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

•Tip 1: For irregular objects, measure volume by water displacement in a calibrated container.
•Tip 2: Dry porous samples like bricks or wood before weighing, or moisture inflates the density.
•Tip 3: Check temperature: water at 4 °C is 1,000 kg/m³ but less dense when hot or frozen.
✗Mistake 1: Do not mix units — mass in kg with volume in litres gives a misleading figure (divide litres by 1,000).
✗Mistake 2: Do not treat table densities as exact; moisture and impurities shift every real-world material.

Expert Note

Specific gravity is dimensionless — it compares a substance's density to water at 4°C (1,000 kg/m³). Materials with specific gravity > 1 sink; < 1 float. In Indian construction, sand typically has a density of 1,450-1,600 kg/m³ and coarse aggregate 1,500-1,700 kg/m³. Always measure dry density for porous materials like bricks and wood, as moisture inflates the reading.

Sources and References

•CRC Handbook of Chemistry and Physics: Density of common substances
•NIST: Reference data on fluid densities
•IS 1077: Standard for brick density — Bureau of Indian Standards

Official sources are linked so you can confirm the current rate yourself. Check the linked page for the latest notification before relying on these figures.

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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