Density Calculator
Calculate density from mass and volume in kg/m³ and g/cm³, and learn how to use it to identify materials or predict whether an object floats.
Results
Density
- g/cm³
- 1
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Educational estimates · not financial advice · free, no signup
Formula / how it works
ρ = m ÷ V. With mass in kg and volume in m³ the result is kg/m³. 1 g/cm³ = 1,000 kg/m³.
Detailed guide
What it is, how to use it, how to read the numbers, common mistakes, a worked example, formulas, and FAQs.
What this calculator is
Density is how much mass is packed into a given volume. Water is about 1,000 kg/m³ (1 g/cm³), steel is roughly 7,850 kg/m³, and air only about 1.2 kg/m³. Because every pure material has a characteristic density, measuring it can help identify a sample, check a casting, or work out whether an object floats. This calculator takes mass in kilograms and volume in cubic metres and returns density in kg/m³ and g/cm³. Students use it in physics and chemistry, makers use it to estimate material weights, and engineers use it to check shipping and structural loads.
When to use / who it helps
- You measured mass and volume of a sample and want its density.
- You want to see if an object will float or sink in water.
- You are trying to identify a metal or material from its density.
- You need to check a density reading against a table.
- You are converting a material specification between kg/m³ and g/cm³.
How to use
Steps
- Enter the mass in kilograms.
- Enter the volume in cubic metres; 1 litre is 0.001 m³ and 1 cm³ is 0.000001 m³.
- Read the density in kg/m³.
- Read the g/cm³ value for comparison with tables.
- For irregular objects, find volume by water displacement.
- Compare with a reference density to identify a material.
How to interpret results
- An object denser than water (above 1,000 kg/m³) sinks in fresh water; a less dense object floats.
- Density depends on temperature and pressure, especially for gases and liquids.
- A hollow or porous object has a lower average density than the solid material.
- Alloys and mixtures have densities between their components.
- Measurement errors in volume tend to dominate the uncertainty.
Common mistakes & gotchas
- Entering volume in litres or cm³ without converting to m³.
- Confusing mass with weight in newtons.
- Using volume of the container rather than the object.
- Ignoring air gaps in powders or granules, which lowers bulk density.
- Comparing density at different temperatures without noting it.
Worked example
Worked example — 1 kg of water in 0.001 m³
- Density = 1 ÷ 0.001 = 1,000 kg/m³.
- Convert to g/cm³: 1,000 kg/m³ ÷ 1,000 = 1 g/cm³.
- A different object: 500 g (0.5 kg) occupying 400 cm³ (0.0004 m³) has density 0.5 ÷ 0.0004 = 1,250 kg/m³.
- Because 1,250 is above 1,000, that object would sink in fresh water.
Result: Water has a density of 1,000 kg/m³ (1 g/cm³).
To load the form's own demo values, tap Try example above the Calculate button.
How to calculate / formula
ρ = m ÷ V. With mass in kg and volume in m³ the result is kg/m³. 1 g/cm³ = 1,000 kg/m³.
Frequently asked questions
What is the formula for density?
Density equals mass divided by volume, ρ = m/V.
What is the density of water?
About 1,000 kg/m³ (1 g/cm³) at roughly 4 °C, slightly lower at higher temperatures.
How do I convert kg/m³ to g/cm³?
Divide by 1,000.
Why do objects float?
They float when their average density is less than the fluid's density.
How do I measure the volume of an irregular object?
Submerge it in water and measure the displaced volume.
Does density change with temperature?
Yes. Most materials expand when heated, so density falls slightly.
Textbook formulas under ideal assumptions. For safety-critical, structural, or regulated work, verify with a qualified engineer and the governing standards. Full disclaimer