Hydrometer Temperature Correction Calculator
Correct your hydrometer specific gravity readings when your wort or beer sample isn't at the hydrometer's calibration temperature. This calculator uses the standard polynomial correction to give you an accurate OG or FG every time, so your ABV and recipe stats are spot on.
Results
Why does temperature correction matter?
Hydrometers measure the density of a liquid, and liquid density changes with temperature. Hot wort is less dense than cold wort, so a hydrometer reads lower than the true gravity when the sample is hot, and higher when very cold.
A reading taken at 80°F on a 60°F-calibrated hydrometer is off by about 3 gravity points — enough to push your calculated ABV off by 0.4% or mislead you about whether fermentation has finished. Always correct, or wait for your sample to reach calibration temperature.
Most homebrewing hydrometers are calibrated at 60°F (15.6°C). Some lab-grade hydrometers calibrate at 68°F (20°C). Check the printed label on your hydrometer.
Correction at a glance (60°F hydrometer)
| Sample temp (°F) | Sample temp (°C) | Approx. correction |
|---|---|---|
| 50 | 10 | −0.6 points |
| 60 (calibration) | 15.6 | 0.0 points |
| 70 | 21 | +0.9 points |
| 80 | 27 | +2.4 points |
| 90 | 32 | +4.2 points |
| 100 | 38 | +6.5 points |
| 120 | 49 | +12.6 points |
| 150 | 66 | +25.8 points |