ABV Calculator (OG/FG)

Calculate alcohol by volume, apparent attenuation, and calories per serving from original and final gravity readings.

Original Gravity (OG)

Final Gravity (FG)

Tab to move between fields

Alcohol by Volume

5.25%

Apparent Attenuation80%

Real Attenuation65.5%

Calories (12 oz)112 cal

How to Use This Calculator

Measure wort specific gravity before fermentation with a hydrometer or refractometer and enter as Original Gravity (OG).
After fermentation is stable (same reading 2–3 days in a row), enter Final Gravity (FG).
Review ABV (%), Apparent Attenuation (%), Real Attenuation (%), and Calories per 12 oz.
Use the ABV vs. Final Gravity line chart to see how alcohol content changes across a range of FG values.

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