🍇 Brewing & food
Brix to Specific Gravity
Convert between Brix, specific gravity and degrees Plato. Enter a value, choose the units, then press Convert.
About the Brix to Specific Gravity
Brix is the percentage of dissolved sucrose by mass in a solution. Specific gravity is the density relative to water. They move together, but not linearly: a 20 Brix solution has a specific gravity of about 1.083, not 1.020. Brewers often use Plato, which is close to Brix but defined from the density of a sucrose solution at 20 °C.
This converter uses the common Brix–SG approximation SG = 1 + Brix ÷ (258.6 − (Brix ÷ 258.2) × 227.1) and inverts it numerically. Plato is calculated from specific gravity with the standard cubic polynomial. For trade and laboratory work, use the official ICUMSA tables at your measured temperature.
How the calculation works
- SG ≈ 1 + B ÷ (258.6 − (B ÷ 258.2) × 227.1) for Brix B.
- Plato = −616.868 + 1111.14·SG − 630.272·SG² + 135.997·SG³.
- Brix and Plato are numerically close but not identical.
- 1 °Brix = 1 g sucrose per 100 g solution.
Reference values
| Brix | Specific gravity | Plato | Approx. sugar |
|---|---|---|---|
| 5 | 1.0195 | 4.9 | 5% |
| 10 | 1.0400 | 9.8 | 10% |
| 12 | 1.0484 | 11.8 | 12% |
| 15 | 1.0610 | 14.8 | 15% |
| 20 | 1.0830 | 20.0 | 20% |
| 30 | 1.1290 | 30.2 | 30% |
Worked example: 10 and 20 Brix
A 10 Brix solution has a specific gravity of about 1.040 and a Plato value of about 9.8. A 20 Brix solution is about 1.083 SG and 20.0 Plato. The two scales are close at low concentration and diverge at high gravity, which is why brewers and winemakers specify which one they are using.
For a brewer, 12 Plato is about 1.048 SG. A refractometer reading taken during fermentation needs an alcohol correction; the raw Brix value will overstate the remaining sugar. Use a hydrometer or a validated correction formula when the reading affects a packaging decision.
Brix, Plato and Baumé
Brix, Plato and Baumé all describe dissolved solids, but they were defined for different industries and do not agree exactly. Brix is calibrated to sucrose solutions and is standard in fruit, wine and soft drinks. Plato is used by brewers and is close to Brix at low concentrations but diverges at high gravity. Baumé is an older scale whose relationship to specific gravity depends on whether it is for liquids heavier or lighter than water.
Converting between them is therefore approximate, and the error grows with concentration. For a brewery, use the Plato table your instruments were calibrated against; for juice and wine, use Brix. Quoting a number without naming the scale makes a comparison meaningless, especially above 20 degrees.