Refractometer Alcohol Adj.

BrewCo Brew Tools

Alcohol in solution skews refractometer readings. This calculator corrects your final reading for an accurate ABV — using either specific gravity or Brix, whichever your refractometer reads in.

How to use it

  1. Take your original reading before fermentation (OG or original Brix).
  2. Take your final refractometer reading after fermentation.
  3. Choose the right tab for your refractometer's scale and enter both readings.
% ABV
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% ABV
Fill in both fields above

Why can't I just use a normal refractometer reading after fermentation?

Refractometers measure how light bends through a liquid, which changes with dissolved sugar — but alcohol also bends light, in the opposite direction to sugar. This makes a raw post-fermentation refractometer reading read too high unless corrected — which is exactly what this calculator does.

More free home brew calculators

Browse our range of refractometers and hydrometers at BrewCo UK.