Density Calculator
Density Formula
Mass
m = ρ × V
Volume
V = m / ρ
Common Densities
Related Calculators
Understanding Density
What is Density?
Density is a measure of how much mass is contained in a given volume. It tells you how tightly matter is packed together. Objects with higher density have more mass per unit volume than objects with lower density.
Density Formula
Density of Common Materials
| Material | g/cm³ | kg/m³ | Notes |
|---|---|---|---|
| Water | 1.00 | 1,000 | Reference standard |
| Ice | 0.92 | 920 | Floats on water |
| Wood (oak) | 0.6-0.9 | 600-900 | Floats |
| Concrete | 2.4 | 2,400 | Building material |
| Aluminum | 2.70 | 2,700 | Lightweight metal |
| Steel | 7.85 | 7,850 | Common metal |
| Copper | 8.96 | 8,960 | Electrical conductor |
| Lead | 11.34 | 11,340 | Heavy metal |
| Gold | 19.32 | 19,320 | Precious metal |
Floating and Sinking
Objects Float When...
An object floats if its density is less than the fluid it's placed in. Wood (ρ ≈ 0.7 g/cm³) floats on water (ρ = 1.0 g/cm³) because wood is less dense.
Objects Sink When...
An object sinks if its density is greater than the fluid. Iron (ρ = 7.87 g/cm³) sinks in water because it's much denser than water.
Specific Gravity
Specific gravity is the ratio of a substance's density to the density of water. Since water has a density of 1 g/cm³, specific gravity is numerically equal to density in g/cm³. A specific gravity of 2.5 means the substance is 2.5 times denser than water.
Practical Applications
- Ship design—ensuring cargo ships float with proper load
- Material selection—choosing lightweight metals for aircraft
- Quality control—checking purity of materials
- Cooking—oils float on water-based liquids
- Battery testing—measuring acid density in car batteries
Frequently Asked Questions
How do I calculate density?
To calculate density, divide mass by volume using the formula: ρ = m/V. For example, if an object has a mass of 100 grams and a volume of 50 cm³, its density is 100/50 = 2 g/cm³.
What is the density formula?
The density formula is ρ = m/V, where ρ (rho) is density, m is mass, and V is volume. You can rearrange this to find mass (m = ρ × V) or volume (V = m/ρ) if you know the other two values.
What is the density of water?
Pure water has a density of 1.00 g/cm³ (or 1000 kg/m³) at 4°C. This makes water a convenient reference standard—objects with density less than 1 g/cm³ float in water, while denser objects sink.
What is specific gravity?
Specific gravity is the ratio of a substance's density to the density of water. Since water's density is 1 g/cm³, specific gravity equals the numerical value of density in g/cm³. A specific gravity of 2.7 (like aluminum) means it's 2.7 times denser than water.