Density Calculator
PrintDensity of Common Materials
| Material | Density (kg/m³) |
|---|---|
| Earth's Atmosphere (sea level) | 1.2 |
| Water (at standard pressure) | 1,000 |
| Ice | 917 |
| The Earth (average) | 5,515 |
| Iron | 7,874 |
| Copper | 8,950 |
| Lead | 11,340 |
| Gold | 19,300 |
| Platinum | 21,450 |
Density is a fundamental physical property of matter defined as an object’s mass per unit volume. In physics and material science, density is represented by the lower-case Greek letter rho (ρ). Understanding density is crucial for fluid dynamics, metallurgy, buoyancy analysis, construction, and chemical manufacturing.
Our free online Density Calculator solves for any unknown variable in the density equation:
- Find Density (ρ): Calculate density by entering known mass and volume.
- Find Volume (V): Determine required container volume from mass and material density.
- Find Mass (m): Compute total weight or mass from volume and material density.
The Density Formula: ρ = m / V
The relationship between density, mass, and volume is expressed algebraically using the Density Formula Triangle:
| Target Variable | Algebraic Formula | Description & Operation |
|---|---|---|
| Density (ρ) | ρ = m ÷ V |
Divide total mass by total volume. |
| Mass (m) | m = ρ × V |
Multiply density by volume. |
| Volume (V) | V = m ÷ ρ |
Divide total mass by density. |
Common Density Units & Conversion Multipliers
Density can be expressed in various metric and imperial units. The official SI base unit is kilograms per cubic meter (kg/m³). The table below shows conversion factors to convert common units into kg/m³:
| Density Unit | Unit Abbreviation | Equivalent in SI Units (kg/m³) |
|---|---|---|
| Kilogram per cubic meter (SI) | kg/m³ | 1.0 kg/m³ |
| Gram per cubic centimeter | g/cm³ | 1,000 kg/m³ |
| Kilogram per liter | kg/L | 1,000 kg/m³ |
| Gram per liter | g/L | 1.0 kg/m³ |
| Pound per cubic foot | lb/ft³ | 16.02 kg/m³ |
| Pound per cubic inch | lb/in³ | 27,680 kg/m³ |
| Pound per US gallon | lb/gal (US) | 119.83 kg/m³ |
Reference Table: Density of Common Materials
Density varies widely across different states of matter and astronomical structures:
| Substance / Material | State of Matter | Density in kg/m³ | Density in g/cm³ |
|---|---|---|---|
| Earth’s Atmosphere (Sea Level) | Gas | 1.2 kg/m³ | 0.0012 g/cm³ |
| Pure Water (at 4°C) | Liquid | 1,000 kg/m³ | 1.000 g/cm³ |
| Planet Earth (Average) | Solid / Core | 5,515.3 kg/m³ | 5.515 g/cm³ |
| Iron | Solid Metal | 7,874 kg/m³ | 7.874 g/cm³ |
| Copper | Solid Metal | 8,950 kg/m³ | 8.950 g/cm³ |
| Tungsten | Solid Metal | 19,250 kg/m³ | 19.250 g/cm³ |
| Gold | Solid Metal | 19,300 kg/m³ | 19.300 g/cm³ |
| Platinum | Solid Metal | 21,450 kg/m³ | 21.450 g/cm³ |
| Atomic Nuclei | Subatomic | 2.3 × 1017 kg/m³ | 2.3 × 1014 g/cm³ |
Effects of Temperature & Pressure on Density
Density is not a static constant; it changes dynamically with ambient environmental conditions:
- Solids & Liquids: Are generally incompressible. Changes in pressure cause negligible density changes. However, increasing temperature causes slight thermal expansion (volume increases, so density decreases slightly).
- Gases: Are highly compressible. According to the Ideal Gas Law (
P·V = n·R·T), an increase in pressure compresses the gas (volume decreases, density increases). Conversely, an increase in temperature causes the gas to expand (volume increases, density decreases). - Water Anomaly: Pure water exhibits unique thermodynamic behavior. Water reaches its maximum density at 4°C (39.2°F) (1,000 kg/m³). Below 4°C down to 0°C, water expands as hydrogen bonds form a crystalline ice lattice. As a result, ice at 0°C has a lower density (≈ 917 kg/m³) than liquid water, allowing ice to float on lakes and oceans.
To convert measurement units before calculating density, use our Conversion Calculator. To determine the volume of 3D objects, visit our Volume Calculator. For molar mass calculations in chemistry, explore our Molecular Weight Calculator.
Frequently Asked Questions (FAQ)
What is the difference between density and specific gravity?
Density is an absolute measure of mass per volume expressed in units like g/cm³ or kg/m³. Specific gravity (relative density) is a dimensionless ratio comparing a material’s density to the density of a reference substance (usually pure water at 4°C for liquids/solids, or air for gases).
Why does ice float on water?
Ice floats because it is less dense than liquid water. As water cools below 4°C and freezes at 0°C, its molecules form an open hexagonal lattice bound by hydrogen bonds. This lattice expands the volume by roughly 9%, lowering the density of ice to 917 kg/m³ compared to liquid water’s 1,000 kg/m³.
How do I convert g/cm³ to kg/m³?
To convert from grams per cubic centimeter (g/cm³) to kilograms per cubic meter (kg/m³), multiply by 1,000:
Density (kg/m³) = Density (g/cm³) × 1000
For example, iron at 7.874 g/cm³ equals 7.874 × 1000 = 7,874 kg/m³.
Does salt water have a higher density than fresh water?
Yes. Dissolving salt (sodium chloride) into water adds mass without significantly increasing total volume. Standard ocean seawater has a density of approximately 1,025 kg/m³ at 15°C, making it more buoyant than fresh water (1,000 kg/m³).