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Beverage ABV calculator

Estimate fermentation ABV from original and final specific gravity using the 131.25 approximation.

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Estimate fermentation ABV from original and final specific gravity using the 131.25 approximation.

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Formula and assumptions
ABV percent = (original gravity - final gravity) times 131.25. Use temperature-corrected hydrometer readings of the same fermentation. Raw post-fermentation refractometer Brix readings need an alcohol correction and cannot be entered as gravity. This approximation is not an alcohol assay or a labeling/tax determination; it is less reliable for strong or unusual fermentations.
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Using Beverage ABV calculator
Estimate fermentation ABV from original and final specific gravity using the 131.25 approximation.
ABV percent = (original gravity - final gravity) times 131.25. Use temperature-corrected hydrometer readings of the same fermentation. Raw post-fermentation refractometer Brix readings need an alcohol correction and cannot be entered as gravity. This approximation is not an alcohol assay or a labeling/tax determination; it is less reliable for strong or unusual fermentations.
Next: Dilution calculator
Next: Percentage calculator
A worked example
For original specific gravity, corrected hydrometer reading = 1.05, final specific gravity, corrected hydrometer reading = 1.01, estimated alcohol by volume (%) = 5.25.
Before you use the result
ABV percent = (original gravity - final gravity) times 131.25. Use temperature-corrected hydrometer readings of the same fermentation. Raw post-fermentation refractometer Brix readings need an alcohol correction and cannot be entered as gravity. This approximation is not an alcohol assay or a labeling/tax determination; it is less reliable for strong or unusual fermentations.
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ToolOctopus. “Beverage ABV calculator.” Updated 2026-09-29. https://tooloctopus.com/beverage-abv-calculator.
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