Density Calculator
Density Calculator: Find Density, Mass or Volume
Density tells you how much matter is packed into a given space. A density calculator finds it from the mass and volume of an object, and it can also work backwards: if you know the density of a material and the size of a piece, it gives the mass, and if you know the mass it gives the volume. Choose what you want to find, enter the two values you have with their units, and the result appears in kilograms per cubic metre, grams per cubic centimetre and pounds per cubic foot, together with the specific gravity.
Quick answer: an object with a mass of 500 g that takes up 250 mL has a density of 2 g/cm³, which is 2,000 kg/m³.
The Density Formula
Density is mass divided by volume. The Greek letter rho is used for it, so the formula reads ρ = m ÷ V. The two other forms come from rearranging it.
The calculator converts every entry to kilograms and cubic metres first, does the sum in those units, and then shows the answer in the units you are likely to need.
Worked Examples
These examples use the same steps as the tool. Try them yourself by choosing a mode and typing the known values.
| Find | Known values | Result |
|---|---|---|
| Density | 500 g in 250 mL | 2 g/cm³ (2,000 kg/m³) |
| Density | 2 lb in 0.05 ft³ | 40 lb/ft³ (640.7 kg/m³) |
| Density | 15.7 kg in 2 L | 7.85 g/cm³ (about steel) |
| Mass | 2.7 g/cm³ and 50 cm³ | 135 g |
| Mass | 7,850 kg/m³ and 0.002 m³ | 15.7 kg |
| Mass | 62.4 lb/ft³ and 10 gal | 83.42 lb |
| Volume | 100 g at 2.7 g/cm³ | 37.04 cm³ |
| Volume | 1 lb of gold at 19.3 g/cm³ | 23.5 cm³ |
Density of Common Materials
Typical values at room temperature are shown below. Real samples vary with purity, moisture and temperature, so treat them as good starting figures rather than exact ones. When you choose a material in the calculator, the density field is filled in for you.
| Material | kg/m³ | g/cm³ | lb/ft³ |
|---|---|---|---|
| Water (4 °C) | 1,000 | 1 | 62.43 |
| Ice | 917 | 0.917 | 57.25 |
| Air (sea level) | 1.225 | 0.001225 | 0.07647 |
| Gasoline | 745 | 0.745 | 46.51 |
| Pine wood | 500 | 0.5 | 31.21 |
| Oak wood | 750 | 0.75 | 46.82 |
| Concrete | 2,400 | 2.4 | 149.8 |
| Glass | 2,500 | 2.5 | 156.1 |
| Aluminium | 2,700 | 2.7 | 168.6 |
| Iron | 7,874 | 7.874 | 491.6 |
| Steel | 7,850 | 7.85 | 490.1 |
| Copper | 8,960 | 8.96 | 559.4 |
| Silver | 10,490 | 10.49 | 654.9 |
| Lead | 11,340 | 11.34 | 707.9 |
| Mercury | 13,530 | 13.53 | 844.9 |
| Gold | 19,300 | 19.3 | 1,205 |
Density Unit Conversions
Density can be written in several unit systems. These quick conversions cover the ones used most often in science, cooking and building work.
| Unit | kg/m³ | g/cm³ or lb/ft³ | lb/gal |
|---|---|---|---|
| 1 g/cm³ | 1,000 kg/m³ | 62.43 lb/ft³ | 8.345 lb/gal |
| 1 kg/L | 1,000 kg/m³ | 62.43 lb/ft³ | 8.345 lb/gal |
| 1 lb/ft³ | 16.02 kg/m³ | 0.016 g/cm³ | 0.1337 lb/gal |
| 1 lb/in³ | 27,680 kg/m³ | 27.68 g/cm³ | 1,728 lb/ft³ |
Specific Gravity
Specific gravity is the density of a material divided by the density of water. Because water is about 1 g/cm³, the specific gravity of a material is almost the same number as its density in g/cm³. Aluminium has a specific gravity of about 2.7 and ice is about 0.92. A value below 1 means the material floats in water, and a value above 1 means it sinks.
Why Floating and Sinking Depend on Density
An object floats when it is less dense than the fluid around it. Ice floats because it is roughly 8% less dense than liquid water, which is why about 92% of an iceberg sits under the surface. Steel sinks as a solid block, yet a steel ship floats because its hollow shape lets the whole vessel have an average density below water. The tip below the results tells you whether your numbers sink or float.
Tips for Accurate Results
Measure mass and volume in matching conditions. Liquids change volume as they warm up, and powders or sand can pack tighter than they pour, which changes the value. For irregular solids, measuring the water displaced in a graduated cylinder is a reliable way to get the volume. Keep the number of significant figures in line with how carefully you measured.
Related Tools
To change between units, use the unit converter, the volume converter or the length converter. The area calculator is handy for working out sizes, and the concrete calculator is useful when you need volumes for a pour.
How to Use This Density Calculator
Choose what to find
Pick Find Density, Find Mass or Find Volume.
Enter the values
Type the two known values, choose a unit for each and use the slider to adjust them.
Pick a material if needed
When density is a known input, choose a material to fill in its typical density.
Read and copy
Check the result in several units, see whether it sinks or floats, then copy it or press Reset.