Example 1
m = 1 kg, V = 0.001 m³ → ρ ≈ 1000 kg/m³.
Density Calculator
Enter mass and volume. The calculator computes density ρ = m/V. A 0.001 m³ liter carton at 1 kg gives 1000 kg/m³, the order of room-temperature water.
From water ρ: buoyant force or hydrostatic pressure.
Result
Mass m (kg) and Volume V (m³). The result shows up here.
How it works
Density is mass per volume: ρ = m/V. Room-temperature water is about 1000 kg/m³. 1 L is 0.001 m³, so 1 kg in a liter gives exactly that 1000 kg/m³. One hundred liters is 0.1 m³: 100 kg in 0.1 m³ is 1000 kg/m³ again. 2 kg in 0.001 m³ is 2000 kg/m³, denser than water. 250 ml is 0.00025 m³.
Volume in this calculator stays in cubic meters. We do not switch it to cubic feet. 1 cm³ is 0.000001 m³, not 1 in the field. Mass in metric is kilograms; after the US switch the label may show pounds. ρ is still kg/m³. A comma and a period are the same V: 0,001 and 0.001.
V must be positive. Zero cubic meters does not divide: no volume, no density. Negative mass will not run. Zero kilograms is rejected. Both fields need a number before 1000 kg/m³ can appear.
Buoyancy F = ρ·V·g and pressure p = ρ·g·h live next door. There g enters. Here density does not depend on g: it is the quotient m/V alone. Specific weight is ρ·g, a different quantity. If you know ρ and V, mass is m = ρ·V. This calculator goes the other way.
The switch does not rewrite a number you already typed: change the unit on an empty field, or convert yourself. Treat 1000 as the order of water, not as temperature or salt in a solution.
Type 1 and 0.001, click Calculate, and match 1000 kg/m³. Then 2 and 0.001: 2000 kg/m³. The header symbol does not weigh a kilogram.
How to use
- In the first field enter mass. In metric that is kilograms: 1 for a liter of water, 1000 for a cubic meter of water. After the US switch the label may say pounds.
- In the second field enter volume in m³. 1 L is 0.001. 1 cm³ is 0.000001. One hundred liters is 0.1. 250 ml is 0.00025.
- Click Calculate. The calculator divides m by V. 1 kg and 0.001 m³ give 1000 kg/m³. 2 kg in that same liter give 2000 kg/m³.
- Zero volume will not run, because you divide by V. Both fields need a number. The result stays in kg/m³ even if mass is in pounds.
- Want buoyancy? Open F = ρ·V·g. A fluid column is on p = ρ g h. Here it stays density, with no g.
Formula
ρ = m / V
SI unit: kg/m3. Volume is always in m3.
ρ, m, and V for a liter of water
Density here is the quotient alone. 1 kg in 0.001 m³ is 1000 kg/m³, water order, no g and no buoyancy.
- ρ
- Density in kg/m³: ρ = m/V. 2 kg in that same liter is 2000 kg/m³, denser than water.
- m
- Mass in kilograms. One hundred liters (0.1 m³) at 100 kg is 1000 kg/m³ again.
- V
- Volume always in m³. 1 L is 0.001. 1 cm³ is 0.000001. Zero cubic meters does not divide.
- kg/m³
- The result unit. It stays SI even if the mass label switches to pounds.
Real-life examples
Example 2
Lighter than water: m = 0.9 kg, V = 0.001 m³.
Example 3
m ≈ 1.2 kg in V = 1 m³.
Example 4
m = 7.8 kg, V = 0.001 m³.
Example 5
m = 0.6 kg in V = 0.001 m³.
Example 6
m = 0.92 kg, V = 0.001 m³.
Example 7
m = 2.4 kg, V = 0.001 m³.
Example 8
m = 8.9 kg, V = 0.001 m³.
Example 9
m = 25 kg, V = 0.02 m³.
Example 10
m = 0.001 kg, V = 0.000001 m³.
Ways to use this calculator
- You check whether 1 kg in 1 L is water density.
- You convert liters to m³ before typing volume.
Frequently asked questions
What is the density of water in this calculator?
About 1000 kg/m³. 1 kg in 0.001 m³, a liter, gives exactly that. One hundred liters at 100 kg is 1000 again.
Why is volume only in m³?
To keep cubic feet out of SI. 1 L = 0.001 m³. 1 cm³ = 0.000001 m³. The field does not know milliliters.
How do I convert liters to m³?
1 L = 0.001 m³. One hundred liters is 0.1 m³. 250 ml is 0.00025 m³. Type cubic meters already.
Does ρ depend on g?
No. Density is m/V. g enters pressure and buoyancy, not this quotient. Specific weight is ρ·g, a different quantity.
What if V = 0?
The calculator rejects zero volume. You divide by V. Both fields need a number before 1000 kg/m³ appears.
Where do I get buoyancy?
On the buoyant-force page, F = ρ·V·g. Here you compute ρ. A fluid column is on p = ρ g h.
How is density different from specific weight?
Density is m/V in kg/m³. Specific weight is ρ·g, force per volume. This calculator stays with m/V.
Can I get mass from ρ and V?
Yes: m = ρ·V. This calculator computes ρ from m and V. You go the other way from the mass formula.
What units is the result in?
Always kg/m³. Mass may switch to lb; density stays SI.
Does a comma in 0.001 work?
Yes. 0,001 and 0.001 are the same V. The calculator does not require a period.
Knowledge sources
The formula is the school one. Units follow SI; NIST SP 330 and BIPM define the measures, not your result.
Page updated in 2026.