How the Specific Gravity Calculator Works
The Specific Gravity Calculator compares a substance density with a reference density, then uses the specific gravity (SG) to convert mass to volume.
Pick the reference
Use water at 4°C (1.000 kg/L), 15.6°C/60°F (0.999 kg/L) or 20°C (0.9982 kg/L) to match your industry standard.
Divide the densities
SG = substance density ÷ reference density. 1.25 ÷ 0.9982 = 1.252.
Enter mass and SG
Type the kilograms and the SG into the calculator.
Read the volume
The result shows liters; the table converts SG to API gravity and degrees Baumé.
Specific Gravity Calculator Formula
The specific gravity formula is SG = ρsubstance ÷ ρreference. Petroleum and chemical trades convert SG into API gravity and Baumé degrees.
- SG
- Specific gravity, unitless
- °API
- American Petroleum Institute (API) gravity
- °Bé
- Baumé degrees for liquids heavier than water
Worked Examples
- Crude oil at 0.876 kg/L (60°F): SG = 0.876 ÷ 0.999 = 0.877, so °API = 141.5 ÷ 0.877 − 131.5 = 29.8°.
- Sulfuric acid at 1.84 kg/L: °Bé = 145 − 145 ÷ 1.84 = 66.2°Bé.
- Brine with SG 1.20: 30 kg ÷ 1.20 = 25.000 L.
Specific Gravity Calculator Conversion Table
An SG of 0.876 equals 30.0° API, the boundary between medium and light crude oil. The table converts SG into API gravity, Baumé degrees and density.
| Specific Gravity | Density (kg/L) | °API | °Baumé | Liters per 1 kg |
|---|---|---|---|---|
| 0.700 | 0.699 | 70.6 | 70.0 | 1.430 |
| 0.750 | 0.749 | 57.2 | 56.7 | 1.335 |
| 0.800 | 0.799 | 45.4 | 45.0 | 1.251 |
| 0.850 | 0.849 | 35.0 | 34.7 | 1.178 |
| 0.876 | 0.875 | 30.0 | 29.8 | 1.143 |
| 0.900 | 0.899 | 25.7 | 25.6 | 1.112 |
| 0.950 | 0.949 | 17.4 | 17.4 | 1.054 |
| 1.000 | 0.999 | 10.0 | 0.0 | 1.001 |
| 1.100 | 1.099 | -2.9 | 13.2 | 0.910 |
| 1.200 | 1.199 | -13.6 | 24.2 | 0.834 |
| 1.400 | 1.399 | -30.4 | 41.4 | 0.715 |
| 1.600 | 1.598 | -43.1 | 54.4 | 0.626 |
| 1.840 | 1.838 | -54.6 | 66.2 | 0.544 |
Density column uses water at 60°F (15.6°C) = 0.999 kg/L. Baumé uses the light-liquid scale (140 ÷ SG − 130) below SG 1.000 and the heavy-liquid scale above.
What is a Specific Gravity Calculator?
A Specific Gravity Calculator is a tool that divides the density of a substance by the density of a reference, usually water, to get a unitless specific gravity.
Specific gravity tells you at a glance whether a liquid floats or sinks on water. SG 0.85 oil floats; SG 1.26 glycerin sinks.
Industries quote SG at different reference temperatures. Petroleum uses 60°F/60°F, European chemistry uses 20°C/4°C, and brewing uses 20°C/20°C. The temperature pair changes the fourth decimal place.
What are the Uses of a Specific Gravity Calculator?
There are 5 main uses of a Specific Gravity Calculator.
Crude oil grading
Refiners classify crude as light, medium or heavy by API gravity.
Acid strength
Plating and battery shops read acid strength from SG or Baumé.
Gemstone testing
Gemologists separate stones by hydrostatic SG.
Fermentation tracking
Winemakers follow sugar conversion through falling SG.
Mineral separation
Mining labs choose heavy liquids for float-sink tests.