Water: 1 kg in 0.001 m³
m = 1 kg, V = 0.001 m³ → ρ ≈ 1000 kg/m³.
Density Calculator
Enter mass and volume. You get ρ in kg/m³. Volume stays SI (m³), as in school physics.
With water density, compute hydrostatic pressure or buoyant force. Weight from mass: F = m·a.
Result
Enter values. The result shows up here.
How it works
Density ρ = m/V tells how much mass sits in a given volume. Room-temperature water is about 1000 kg/m³. A one-litre carton is V = 0.001 m³, so m = ρ·V ≈ 1 kg.
Volume in this calculator is always in m³ (SI). We do not switch it to cubic feet, to keep conversion factors safe. If you have litres: 1 L = 0.001 m³. For cm³: 1 cm³ = 10⁻⁶ m³.
Density feeds liquid pressure (p = ρ·g·h) and buoyancy (F = ρ·V·g). Once you know ρ, open hydrostatic pressure or buoyant force.
Mass and volume must be positive. The result is in kg/m³. Gases are far less dense than liquids; metals are usually much denser.
How to use
- Enter mass m in kilograms (US switch converts to pounds).
- Enter volume V in m³ (always SI).
- Read ρ = m/V in kg/m³.
- The chart shows ρ at fixed mass while volume changes.
Formula
ρ = m / V
SI unit: kg/m3. Volume always in m3.
Real-life examples
Oil 0.9 kg / 0.001 m³
Lighter than water: m = 0.9 kg, V = 0.001 m³.
Room air (scale)
m ≈ 1.2 kg in V = 1 m³.
Steel: 7.8 kg / 0.001 m³
m = 7.8 kg, V = 0.001 m³.
Floating wood
m = 0.6 kg in V = 0.001 m³.
Ice cube 0.92 kg
m = 0.92 kg, V = 0.001 m³.
Concrete 2.4 kg / litre
m = 2.4 kg, V = 0.001 m³.
Copper 8.9 kg / litre
m = 8.9 kg, V = 0.001 m³.
Bag 25 kg / 0.02 m³
m = 25 kg, V = 0.02 m³.
Drop 1 g / 1 cm³
m = 0.001 kg, V = 0.000001 m³.
Ways to use this calculator
- Check whether a substance is denser than water.
- Turn a sample mass into ρ when volume is known.
Frequently asked questions
What is the density of water?
About 1000 kg/m³ (it depends slightly on temperature). One litre then weighs about 1 kg.
Why is volume only in m³?
Volume stays SI (m³), as in US school physics too.
How do I convert litres to m³?
1 L = 0.001 m³. One hundred litres is 0.1 m³.
Does ρ depend on g?
No. Density is m/V. g appears later in pressure and buoyancy.
How does this link to buoyancy?
Buoyant force F = ρ·V·g uses liquid density. See buoyant force.
How does this link to water pressure?
p = ρ·g·h. Open hydrostatic pressure.
Why are m ≤ 0 or V ≤ 0 rejected?
Mass and volume must be positive. Zero or negative values are not physical here.
How is density different from specific weight?
Density is m/V. Specific weight is ρ·g (force per volume).
Can I get mass from ρ and V?
Yes: m = ρ·V. This page computes ρ from m and V; check the inverse with the water example.
What units does the result use?
Always kg/m³. The mass field may switch to lb, but density stays in SI.
Where is pressure p = F/S?
Canonical page: pressure p = F/S.