Density Unit Converter
Convert engineering quantities quickly and consistently.
Quick Access:
Manual Conversion Shortcut
Select units to view formula.
Equivalent Units
Select a quantity to see equivalents.
Standard Reference Tables
SI System
| SI Unit | Equivalent |
|---|---|
| 1 kg/m³ | 0.001 kg/L |
| 1,000 kg/m³ | Density of Water (SG Base) |
FPS System
| FPS Unit | Equivalent |
|---|---|
| 1 lb/ft³ | 0.13368 lb/US gal |
| 10 API Gravity | Specific Gravity = 1.0 (Water) |
CGS System
| CGS Unit | Equivalent |
|---|---|
| 1 g/cm³ | 1,000 kg/m³ (SI) |
| 1 g/cm³ | 1 g/mL |
Density
What is Density and API Gravity?
Density is the mass of a substance per unit volume. In the petroleum and chemical industries, density is frequently expressed as Specific Gravity (SG)—a dimensionless ratio of the fluid's density compared to water—or as API Gravity, an empirical scale used to measure how heavy or light a petroleum liquid is compared to water.
Fluid characterization relies heavily on density conversions for:
- Separation Equipment: Sizing settling internals and calculating Stokes' Law droplet settling velocities.
- Hydrostatic Head: Determining base pressure at the bottom of columns and tanks.
- Crude Valuation: Classifying light vs. heavy crude oils.
This tool converts universally between standard density (kg/m³, lb/ft³), Specific Gravity (SG), and the petroleum industry's API Gravity scale.