Fermentation Calculator

Enter your Original Gravity (OG) and Final Gravity (FG) readings to calculate Alcohol by Volume (ABV) and Apparent Attenuation.

Gravity readings are typically measured with a hydrometer.

Original Gravity (OG):

Final Gravity (FG):

Decimal Places for Results:

Fermentation Results

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ABV Formula Used: $$(OG - FG) \times 131.25$$

Apparent Attenuation Formula: $$((OG - FG) / (OG - 1)) \times 100$$

These formulas are common approximations. More precise formulas exist, especially for higher gravity fermentations or specific yeast strains.