Popular conversions
1 pairsKilogram per Cubic Meter ↔ Gram per Cubic Centimeter
kg/m³ ↔ g/cm³
Unit guides
2 unitsDetailed guide to Density
Density describes how much mass is packed into a given volume. It determines whether an object floats or sinks and is a key input for hydrostatic pressure and fluid-flow calculations.
Kilogram per cubic meter is the SI derived unit of density, while gram per cubic centimeter is common in laboratory and chemistry contexts.
- Physical quantity
- Density (mass per volume)
- SI unit
- Kilogram per cubic meter
- SI symbol
- kg/m³
- Water density
- ≈ 1000 kg/m³ (at 4 °C)
- Typical use
- Materials, fluids and hydrostatic calculations
Density, mass and volume
Density relates mass to volume. Kilograms per cubic metre is the SI unit, while grams per millilitre and pounds per cubic foot are common in laboratory, material and US customary contexts.
A material's density can change with temperature, pressure and composition. Use the stated test conditions when comparing a specification or estimating mass from volume.
What is density?
Density is mass divided by volume: ρ = m / V. It tells you how heavy a substance is relative to how much space it occupies.
A large numerical range separates common materials: air is about 1.2 kg/m³, water about 1000 kg/m³, and steel about 7850 kg/m³.
kg/m³ and g/cm³
One kilogram per cubic meter equals exactly 0.001 grams per cubic centimeter, since the two units differ by a factor of 1000.
Laboratories often use g/cm³ for small samples, while engineering and scientific work generally defaults to kg/m³.
How is density used in engineering?
Density is a direct input to the hydrostatic pressure formula (ΔP = ρgh) and to the Reynolds number, which determines whether a fluid flow is laminar or turbulent.
Comparing the densities of materials also guides selection in construction, shipping and manufacturing, where weight per unit volume affects cost and performance.
Unit comparison table
| Unit | Symbol | SI equivalent | System | Common use |
|---|---|---|---|---|
| Kilogram per Cubic Meter | kg/m³ | SI reference unit | SI | Materials, fluids and engineering |
| Gram per Cubic Centimeter | g/cm³ | 1 g/cm³ = 1,000 kg/m³ | Metric | Laboratory and material-property data |
Density units
| Unit | Symbol | Information |
|---|---|---|
| Kilogram per Cubic Meter | kg/m³ | View unit guide |
| Gram per Cubic Centimeter | g/cm³ | View unit guide |