Australia
Tier 1
ABV calculator
Original and final gravity in, alcohol by volume and by weight out. Both the standard and the high-gravity formula.
Free·No sign-up·Last checked 2026-08-27
Formula
ABV% = (OG − FG) × 131.25
ABW% = ABV% × 0.789
Worked example. OG 1.052, FG 1.010 → (1.052 − 1.010) × 131.25 = 5.51% ABV, 4.35% ABW
Questions
The 131.25 multiplier is a linear approximation calibrated for ordinary beer strengths. Above roughly 8% ABV it overstates the result, so the alternate formula corrects for the non-linear relationship between gravity and alcohol content.
Yes, if your readings were not taken at the hydrometer's calibration temperature, usually 20°C. An uncorrected warm reading runs low.
Alcohol by weight — ABV multiplied by 0.789, the density of ethanol relative to water. Australian labels use ABV, but ABW is still useful for comparing calorie and standard-drink calculations.
A stuck fermentation, a bad yeast pitch, or unfermentable sugars can all leave FG higher than the recipe predicted. The calculator still gives an accurate ABV for whatever OG and FG you measured.
Which formula?
The standard formula drifts high above roughly 8% ABV. Use the alternate one for strong beer, wine, mead and cider.