Beer Gravity Calculator
Homebrewers and professional brewers use three closely related scales to measure the sugar content of wort and beer: specific gravity (SG), degrees Plato, and degrees Brix. Specific gravity compares the density of the wort to water (1.000) and is the most common scale for homebrewing, measured with a hydrometer. Degrees Plato expresses dissolved sugar as a weight percentage and is the professional brewing standard, particularly in Europe. Degrees Brix is essentially identical to Plato and is used in winemaking and by refractometers. All three scales carry the same information. This calculator lets you enter a value on any one scale and instantly see the equivalent on the other two. It also accepts optional final gravity to calculate estimated ABV using the standard simplified formula (OG - FG) x 131.25. The conversion between SG and Plato uses the precise cubic polynomial formula established in brewing science, giving more accurate results than the simple (SG - 1) x 250 approximation.
Optional: estimate ABV
Gravity conversion reference table
| SG | Degrees Plato | Degrees Brix | Typical style |
|---|---|---|---|
| 1.020 | 5.07 | 5.07 | Light session beer |
| 1.040 | 9.99 | 9.99 | Light lager |
| 1.050 | 12.39 | 12.39 | Standard ale |
| 1.060 | 14.74 | 14.74 | IPA / amber ale |
| 1.080 | 19.32 | 19.32 | Strong ale / porter |
| 1.100 | 23.77 | 23.77 | Barleywine |
Beer gravity: frequently asked questions
What is the difference between specific gravity, Plato, and Brix?
All three measure the sugar content of a liquid. Specific gravity (SG) compares the density of the liquid to water (1.000). Degrees Plato (P) expresses the percentage of dissolved sugars by weight. Degrees Brix (Bx) is also sugar percentage by weight and is nearly identical to Plato for beer wort. Plato is used by professional brewers; Brix is used in winemaking and viticulture; SG is used by most homebrewers.
How do I convert specific gravity to Plato?
The precise conversion formula is: Plato = -616.868 + 1111.14 * SG - 630.272 * SG^2 + 135.997 * SG^3. A simpler approximation is: Plato = (SG - 1) * 250. For example, SG 1.048 equals approximately 11.9 degrees Plato. This calculator uses the precise polynomial formula.
What is the difference between Plato and Brix?
Plato and Brix are almost identical for pure sucrose solutions. For beer wort, they differ slightly because wort contains a mixture of sugars (glucose, maltose, maltotriose) rather than pure sucrose. The difference is typically less than 0.1 degrees for standard beer gravities. In practice, homebrewers treat them as interchangeable.
Can I use a refractometer to measure final gravity?
Refractometers measure Brix/Plato and are accurate for original gravity of unfermented wort. After fermentation, alcohol in the beer distorts the refractometer reading, making it inaccurate for FG measurement. Hydrometer readings are more reliable for final gravity. If using a refractometer for FG, a correction formula is required.
What ABV can I expect from a wort at 12 degrees Plato?
12 degrees Plato corresponds to approximately SG 1.048. Assuming full attenuation to around 2.5 degrees Plato (FG approximately 1.010), the ABV would be approximately (1.048 - 1.010) * 131.25 = 4.99%, roughly 5% ABV. Actual ABV depends on yeast attenuation characteristics.
References
- American Society of Brewing Chemists: ASBC Methods of Analysis.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.