Density Calculator: Mass, Volume and ρ
Solve density, mass or volume from the other two. Switch units such as kg/m³, g/cm³ and lb/ft³, see the formula ρ = m / V and every step, free and private in your browser.
Fill in all but one field: the empty field is the one you solve for.
About the Density Calculator
The Density Calculator solves the density formula for whichever value you leave empty. Fill in any two of Density, Mass and Volume, and the third appears as you type. The page shows the formula in standard notation with the solved symbol highlighted, then a one-line substitution such as 0.5 kg ÷ 0.00025 m³ = 2,000 kg/m³, so you can see exactly where the number came from.
Density tells you how much matter is packed into a given space. A block of lead and a block of foam can have the same volume, yet the lead is far heavier because its density is far higher. The formula is the same for solids, liquids and gases, as long as the density is uniform through the sample.
How to use the density calculator
Steps
- Type your two known values into their fields. Leave the one you want to find empty.
- Pick a unit for each field. Density offers kg/m³, g/cm³, g/mL, lb/ft³ and lb/in³, mass offers kg, g, mg, lb, oz and tonnes, and volume offers m³, litres, mL, cm³, ft³, in³ and US gallons.
- Read the answer under the formula. The answer's unit follows the unit of the empty field, so change it to see the same result in another unit.
- Press Clear all to start again.
If you fill in all three fields, the calculator asks you to clear one, because it cannot tell which value to solve. If you fill in fewer than two, it shows a hint instead. Density, mass and volume must be greater than zero, and a message appears beside the field if a value is not allowed.
Formula
Here ρ (rho) is density, m is mass and V is volume. In SI units density is measured in kilograms per cubic metre, and 1 g/cm³ equals 1,000 kg/m³.
Worked examples
Example 1: find the density
A sample has a mass of 0.5 kg and a volume of 0.00025 m³. Then ρ = 0.5 ÷ 0.00025 = 2,000 kg/m³, which is 2 g/cm³.
Example 2: find the volume
How much space does 2 kg of water take up? Water is about 1,000 kg/m³, so V = 2 ÷ 1,000 = 0.002 m³, which is 2 litres.
Example 3: find the mass
An iron part has a volume of 150 cm³. Iron is about 7.87 g/cm³, so m = 7.87 × 150 = 1,180.5 g, or roughly 1.18 kg.
Density of common materials
| Material | Density (kg/m³) | Density (g/cm³) |
|---|---|---|
| Air (sea level, 15 °C) | 1.225 | 0.001225 |
| Oak wood (varies) | 750 | 0.75 |
| Ice | 917 | 0.917 |
| Water (about 4 °C) | 1,000 | 1 |
| Aluminium | 2,700 | 2.7 |
| Iron | 7,870 | 7.87 |
| Copper | 8,960 | 8.96 |
| Silver | 10,490 | 10.49 |
| Lead | 11,340 | 11.34 |
| Mercury | 13,534 | 13.534 |
| Gold | 19,320 | 19.32 |
These are typical values at room conditions. Real materials vary with temperature, purity and, for wood, moisture, so use a measured value when accuracy matters.
Tips
- Keep units consistent. The calculator converts for you, but mixing grams with cubic metres by hand is a common source of errors.
- Water is a handy reference: 1 g/mL, 1 kg/L and 1,000 kg/m³ are all the same density.
- An object floats in a liquid when its density is lower than the liquid's.
Privacy
Nothing is uploaded; every calculation runs in your browser and never leaves your device.
Related tools
Use the Mass Converter and the Volume Converter to translate a measurement before you type it in, and the Pressure Calculator for the related force-over-area relationship.
Frequently asked questions
How do I calculate density?
Divide mass by volume: density = mass ÷ volume. A sample of 0.5 kg that fills 0.00025 m³ has a density of 2,000 kg/m³. Enter the mass and volume and leave the density field empty, and the calculator does the division and shows the step.
How do I find mass or volume from density?
Leave that field empty and fill in the other two. Mass equals density times volume, and volume equals mass divided by density. For example, 2 kg of water at 1,000 kg/m³ fills 0.002 m³, which is 2 litres.
What units can I use?
Density offers kg/m³, g/cm³, g/mL, lb/ft³ and lb/in³. Mass offers kg, g, mg, lb, oz and metric tonnes. Volume offers m³, litres, mL, cm³, ft³, in³ and US gallons. Each field has its own unit, so you can mix them freely.
What is the density of water?
About 1,000 kg/m³ near 4 °C, which is the same as 1 g/cm³, 1 g/mL or 1 kg/L. It changes slightly with temperature, and the calculator uses the value you type, not a built-in one.
Why does the calculator say to clear a field?
Density, mass and volume are linked by one equation, so any two determine the third. If all three are filled, the calculator cannot tell which one to solve. Clear the one you want to find.
Why must the values be greater than zero?
A physical sample has positive mass and takes up positive volume, so its density is positive too. Zero or negative entries are flagged next to the field, and no answer is calculated until they are fixed.
Is my data sent anywhere?
No. The density, mass and volume you type stay in this browser tab: nothing is uploaded, stored or shared with a server, so you can safely enter private figures from your own project.