Density Calculator · Practical guide
How to Find Mass from Density and Volume
Mass equals density times volume — two liters of water is two kilograms, and the same trick works for steel, fuel, and air.
At a glance
Quick answer
To find mass, multiply density by volume: M = D × V. Two liters of water (0.002 m³) at 1,000 kg/m³ have a mass of exactly 2 kg, and a 0.02 m³ block of steel at 7,850 kg/m³ has a mass of 157 kg.
Interactive tool
Density Calculator
Enter your own values, then compare the result with the examples below.
Results
The Formula
Density, mass, and volume form one equation: Mass = Density × Volume. Enter density and volume above, leave mass blank, and the result appears with the density echoed in kg/m³, g/cm³, and lb/ft³.
Worked Examples
| Scenario | Density | Volume | Mass |
|---|---|---|---|
| Bottle of water | 1,000 kg/m³ | 0.002 m³ | 2 kg |
| Steel block | 7,850 kg/m³ | 0.02 m³ | 157 kg |
| Fuel tank of gasoline | 750 kg/m³ | 0.05 m³ | 37.5 kg |
Practical Uses
- Estimate the weight of a material order from its dimensions before shipping.
- Check how much fuel a tank really holds in kilograms, not just liters.
- Verify whether a claimed solid-gold item has the right heft for its size.
Watch the Units
The multiplication only works when units match: kg/m³ with cubic meters, or g/cm³ with cubic centimeters. If your volume is in liters, remember 1 liter = 0.001 m³ = 1,000 cm³. Mismatched units are the most common source of wrong answers — the calculator's multi-unit display helps you catch them.
Frequently Asked Questions
How do I convert liters to cubic meters for the formula?
Divide liters by 1,000: one liter is 0.001 m3. So a 50-liter tank has a volume of 0.05 m3, which pairs directly with a density in kg/m3.
Can I find volume instead of mass with the same formula?
Yes — rearranged, Volume = Mass / Density. Enter mass and density above and the calculator solves for volume.
Where do I find a material's density?
Standard density tables list values for common materials — water 1,000 kg/m3, aluminum 2,700, steel about 7,850, gold 19,320. For mixtures, measure mass and volume and compute density directly.
Does temperature affect the answer?
Slightly. Most materials expand when heated, so their density drops a few percent across everyday temperature swings. The calculator assumes constant conditions, which is fine for typical estimates.