Alcohol By Volume ABV Calculator | Brewer's Friend
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Alcohol By Volume ABV Calculator

This calculator determines the ABV of your beer based on the gravity change before and after fermentation. If you took an original gravity reading (or had estimated OG), and also took a final gravity (FG) reading prior to adding priming sugar at bottling you can find out your batch's alcohol by volume ABV.
Alcohol By Volume Calculator:
Gravity Unit:
Original Gravity (OG):
Final Gravity (FG):
Equation:

(see below for more information)
 

Alcohol By Volume:
Apparent Attenuation:
Calories:
Original Gravity:
Final Gravity:

Calculating Beer ABV: Using OG and FG


Original gravity (OG) measures how much sugar is present in the wort before it is fermented. The final gravity (FG) is how much sugar is left over when fermentation is done. A lower final gravity indicates a dry or crisp flavor, while a higher final gravity indicates a sweet or malty flavor. The size of the gap between OG and FG can be used to calculate how much alcohol the beer contains.

This calculator allows you to choose between the standard equation or the alternate equation. If you don't know the difference, just stick with the standard equation. Read more about this update here. These are the equations used to calculate beer alcohol content in each method:

Standard ABV Formula:

ABV = (OG – FG) * 131.25

Alternate ABV Formula:

ABV = (76.08 * (OG - FG) / (1.775 - OG)) * (FG / 0.794)


The calculator supports Plato and SG for inputs and reports apparent attenuation, calories, and the OG/FG in both sugar scales. The calories equation is independent of the ABV equation, and is derived from ["Caloric Content, Beer-33" in: American Society of Brewing Chemists, 1992, Methods of Analysis of the ASBC. American Society of Brewing Chemists; Homebrew Digest 800-9], complete details here: http://hbd.org/ensmingr/.

Remember that hydrometer readings need to be temperature corrected. Try our Hydrometer Temperature Adjustment Calculator.

For readings taken with a refractometer, please see our Refractometer Calculator.

Essential Brewing Terms: Specific Gravity, ABV, and More

This section defines key terms related to brewing and alcohol calculations to help you better understand the brewing process and use our calculators effectively.

Original Gravity (OG)
The specific gravity of wort before fermentation begins. It measures the density of sugars available for yeast to convert into alcohol. A higher OG indicates a potentially stronger beer.
Final Gravity (FG)
The specific gravity of beer after fermentation is complete. It reflects the remaining unfermented sugars and helps determine how much sugar was converted to alcohol. Lower FG generally indicates a drier beer with higher alcohol content.
Specific Gravity
A measurement of a liquid's density compared to water. Brewers use it to track the progress of fermentation and calculate alcohol content in beer. Tools like hydrometers and refractometers are used to measure specific gravity.
Alcohol by Volume (ABV)
The percentage of alcohol present in a finished beer, indicating its strength and potency. Calculating ABV involves using the original and final gravity readings in a specific formula.
ABV Formula
The mathematical equation used to calculate alcohol content based on original gravity and final gravity. A common formula is: (OG - FG) x 131.25. Our ABV calculator simplifies this process for you.
Hydrometer
A tool used to measure the specific gravity of liquids, essential for brewers to determine OG and FG for ABV calculations and monitor fermentation progress.
Refractometer
An alternative tool for measuring specific gravity, often preferred for small samples and requiring only a drop of liquid for measurement.
Attenuation
The percentage of sugars converted into alcohol during fermentation. It is calculated by comparing the original and final gravity and indicates the efficiency of the yeast and the dryness of the final beer.
Fermentation
The process where yeast consumes sugars in wort and produces alcohol and carbon dioxide, transforming wort into beer.
NEXT: To calculate your batch's bitterness in the home brewing standard international bittering units (IBUs), see our IBU calculator.

Thanks for using our calculator. You might be interested in the Complete Recipe Builder. Recipes can be saved, printed, shared, and brewed for complete record keeping.

Click Here To Try The Complete Recipe Calculator


Legal Disclaimer: The Brewer's Friend ABV calculator is for entertainment purposes and should not be used for professional brewing. No warranty or guarantee of accuracy is provided on the information provided by this calculator.