OG · FG · ABV
Enter the readings you took and leave the rest blank. The calculator works out what it can and shows every step. Your numbers are blue; calculated numbers are orange, including what each empty field should read.
No alcohol yet, so neither reading needs an alcohol correction.
Refractometer: the raw reading off the prism. Hydrometer: degassed and corrected for temperature.
Leave blank to calculate it, or enter a known or target ABV to work backward.
Each bar covers every combination of reading errors up to the amounts above, and the dot is the best estimate. One row per alcohol-correction model; the highlighted row is the model chosen in the steps below.
Refractometers are scaled for sugar in water. Wort carries other solids, so the raw reading runs a few percent high, and dividing by your factor gives true °Bx.Refractometers are scaled for sugar in water, and must is nearly all sugar, so the factor is usually close to 1.000. It still absorbs your refractometer's own error, so it's worth calibrating once. How to find your factor.
A refractometer is scaled for sugar dissolved in water. Wort also carries proteins and other solids that bend light a little more, so a refractometer usually reads wort a few percent high. The wort correction factor is how much high your instrument reads. 1.040 is a common default for beer, but refractometers vary, and some brewers find theirs closer to 1.00.
For wine, cider and mead, start at 1.000. Must is nearly all sugar, so there is little to correct beyond your refractometer's own error. The same calibration finds that error.
Repeat on several batches and average the results. Single measurements commonly scatter by 0.01 to 0.02, so one reading is not enough to trust. If you also take both final readings on those batches, the Checks panel shows which alcohol-correction model fits your beer best.