Scientific Density & Specific Gravity Converter
Convert between kg/m³, g/cm³ (g/mL), lb/ft³, lb/US gallon, specific gravity relative to water at 4°C, and petroleum American Petroleum Institute (°API) gravity.
5 Units Available
| Unit Name | Symbol | Converted Value | Copy |
|---|---|---|---|
| Kilograms per cubic meter | kg/m³ | 100 | |
| Grams per cubic cm (g/mL) | g/cm³ | 0.1 | |
| Pounds per cubic foot | lb/ft³ | 6.2428 | |
| Pounds per US gallon | lb/gal | 0.8345 | |
| Specific Gravity (vs Water 4°C) | SG | 0.1 |
What is Density and Specific Gravity?
Density measures mass per unit volume ($\rho = m / V$), having SI dimensions $[M][L]^{-3}$ and base units $\text{kg/m}^3$.
Specific gravity (SG) is the dimensionless ratio of a substance's density to the density of pure water at 4°C ($1,000\,\text{kg/m}^3$). In the petroleum industry, density is universally indexed via API gravity: ${^\circ}\text{API} = (141.5 / \text{SG}) - 131.5$.
Formula & Step-by-Step Calculation
Mathematical relationships between density, specific gravity, and API gravity.
Worked Step-by-Step Examples
Convert 0.85 specific gravity (light crude oil) to kg/m³ and °API.
Common Real-World & Academic Use Cases
- ✓ Petroleum crude oil grade classification (Light, Medium, Heavy, Extra-Heavy)
- ✓ Hydrometer brewing and chemical fermentation specific gravity monitoring
- ✓ Material science alloy selection and naval buoyancy displacement engineering
- ✓ Drilling mud density optimization for borehole hydrostatic control
How to Use the Scientific Density & Specific Gravity Converter
Enter Density
Input density or specific gravity value.
Select Source Unit
Choose kg/m³, g/cm³, lb/gal, SG, or °API.
Review Benchmark Comparison
Compare against reference liquids (Water, Ethanol, Engine Oil, Mercury).
Frequently Asked Questions
Q: What is high API gravity in crude oil?
Crude oil with an API gravity greater than 31.1° is classified as light crude (lower density), which yields higher percentages of gasoline and diesel when refined.