How to Calculate ABV with Specific Gravity Readings

While perfectly calculating alcohol by volume (ABV) can require expensive equipment and skills that surpass the average homebrewer, ABV can be estimated fairly accurately with two gravity readings and some very simple math. To correctly calculate the ABV of your beer, you must take a specific gravity reading both before you ferment the wort and after fermentation has completely finished. This pre-fermentation reading is called the “Original Gravity” and the post-fermentation reading is known as the “Final Gravity”.

Most homebrewers use a hydrometer or refractometer to take gravity readings throughout the process. If you’re just getting started, we recommend using a hydrometer, which is cheaper, easier to use, and a bit more foolproof. If you aren’t sure how to take your gravity readings, check out our article here about how to use a hydrometer to take gravity readings

Once you have successfully taken your OG and FG readings, you the following formula to calculate your ABV. Simply put, first subtract your FG from you OG, and then multiply the difference by 131.25. 

(OG-FG) x 131.25 = ABV

That’s a simple formula, but if for some reason you don’t feel like revisiting algebra (remember your order of operations!), you can just plug your OG and FG readings into this calculator to get your ABV:

ABV Chart

Use the chart below to estimate your alcohol by volume (ABV) by comparing the Original Gravity (OG) measurements (rows) and Final Gravity (FG) measurements (columns)
  Final Gravity                         
0.9900.9920.9940.9960.9981.0001.0021.0041.0061.0081.0101.0121.0141.0161.0181.0201.0221.0241.0261.0281.0301.0321.0341.0361.0381.040
Original Gravity1.0203.93.73.43.22.92.62.42.11.81.61.31.10.80.50.30.0----------
1.0224.23.93.73.43.22.92.62.42.11.81.61.31.10.80.50.30.0---------
1.0244.54.23.93.73.43.22.92.62.42.11.81.61.31.10.80.50.30.0--------
1.0264.74.54.23.93.73.43.22.92.62.42.11.81.61.31.10.80.50.30.0-------
1.0285.04.74.54.23.93.73.43.22.92.62.42.11.81.61.31.10.80.50.30.0------
1.0305.35.04.74.54.23.93.73.43.22.92.62.42.11.81.61.31.10.80.50.30.0-----
1.0325.55.35.04.74.54.23.93.73.43.22.92.62.42.11.81.61.31.10.80.50.30.0----
1.0345.85.55.35.04.74.54.23.93.73.43.22.92.62.42.11.81.61.31.10.80.50.30.0---
1.0366.05.85.55.35.04.74.54.23.93.73.43.22.92.62.42.11.81.61.31.10.80.50.30.0--
1.0386.36.05.85.55.35.04.74.54.23.93.73.43.22.92.62.42.11.81.61.31.10.80.50.30.0-
1.0406.66.36.05.85.55.35.04.74.54.23.93.73.43.22.92.62.42.11.81.61.31.10.80.50.30.0
1.0426.86.66.36.05.85.55.35.04.74.54.23.93.73.43.22.92.62.42.11.81.61.31.10.80.50.3
1.0447.16.86.66.36.05.85.55.35.04.74.54.23.93.73.43.22.92.62.42.11.81.61.31.10.80.5
1.0467.47.16.86.66.36.05.85.55.35.04.74.54.23.93.73.43.22.92.62.42.11.81.61.31.10.8
1.0487.67.47.16.86.66.36.05.85.55.35.04.74.54.23.93.73.43.22.92.62.42.11.81.61.31.1
1.0507.97.67.47.16.86.66.36.05.85.55.35.04.74.54.23.93.73.43.22.92.62.42.11.81.61.3
1.0528.17.97.67.47.16.86.66.36.05.85.55.35.04.74.54.23.93.73.43.22.92.62.42.11.81.6
1.0548.48.17.97.67.47.16.86.66.36.05.85.55.35.04.74.54.23.93.73.43.22.92.62.42.11.8
1.0568.78.48.17.97.67.47.16.86.66.36.05.85.55.35.04.74.54.23.93.73.43.22.92.62.42.1
1.0588.98.78.48.17.97.67.47.16.86.66.36.05.85.55.35.04.74.54.23.93.73.43.22.92.62.4
1.0609.28.98.78.48.17.97.67.47.16.86.66.36.05.85.55.35.04.74.54.23.93.73.43.22.92.6
1.0629.59.28.98.78.48.17.97.67.47.16.86.66.36.05.85.55.35.04.74.54.23.93.73.43.22.9
1.0649.79.59.28.98.78.48.17.97.67.47.16.86.66.36.05.85.55.35.04.74.54.23.93.73.43.2
1.06610.09.79.59.28.98.78.48.17.97.67.47.16.86.66.36.05.85.55.35.04.74.54.23.93.73.4
1.06810.210.09.79.59.28.98.78.48.17.97.67.47.16.86.66.36.05.85.55.35.04.74.54.23.93.7
1.07010.510.210.09.79.59.28.98.78.48.17.97.67.47.16.86.66.36.05.85.55.35.04.74.54.23.9
1.07210.810.510.210.09.79.59.28.98.78.48.17.97.67.47.16.86.66.36.05.85.55.35.04.74.54.2
1.07411.010.810.510.210.09.79.59.28.98.78.48.17.97.67.47.16.86.66.36.05.85.55.35.04.74.5
1.07611.311.010.810.510.210.09.79.59.28.98.78.48.17.97.67.47.16.86.66.36.05.85.55.35.04.7
1.07811.611.311.010.810.510.210.09.79.59.28.98.78.48.17.97.67.47.16.86.66.36.05.85.55.35.0
1.08011.811.611.311.010.810.510.210.09.79.59.28.98.78.48.17.97.67.47.16.86.66.36.05.85.55.3
1.08212.111.811.611.311.010.810.510.210.09.79.59.28.98.78.48.17.97.67.47.16.86.66.36.05.85.5
1.08412.312.111.811.611.311.010.810.510.210.09.79.59.28.98.78.48.17.97.67.47.16.86.66.36.05.8
1.08612.612.312.111.811.611.311.010.810.510.210.09.79.59.28.98.78.48.17.97.67.47.16.86.66.36.0
1.08812.912.612.312.111.811.611.311.010.810.510.210.09.79.59.28.98.78.48.17.97.67.47.16.86.66.3
1.09013.112.912.612.312.111.811.611.311.010.810.510.210.09.79.59.28.98.78.48.17.97.67.47.16.86.6
1.09213.413.112.912.612.312.111.811.611.311.010.810.510.210.09.79.59.28.98.78.48.17.97.67.47.16.8
1.09413.713.413.112.912.612.312.111.811.611.311.010.810.510.210.09.79.59.28.98.78.48.17.97.67.47.1
1.09613.913.713.413.112.912.612.312.111.811.611.311.010.810.510.210.09.79.59.28.98.78.48.17.97.67.4
1.09814.213.913.713.413.112.912.612.312.111.811.611.311.010.810.510.210.09.79.59.28.98.78.48.17.97.6
1.10014.414.213.913.713.413.112.912.612.312.111.811.611.311.010.810.510.210.09.79.59.28.98.78.48.17.9
1.10214.714.414.213.913.713.413.112.912.612.312.111.811.611.311.010.810.510.210.09.79.59.28.98.78.48.1
1.10415.014.714.414.213.913.713.413.112.912.612.312.111.811.611.311.010.810.510.210.09.79.59.28.98.78.4
1.10615.215.014.714.414.213.913.713.413.112.912.612.312.111.811.611.311.010.810.510.210.09.79.59.28.98.7
1.10815.515.215.014.714.414.213.913.713.413.112.912.612.312.111.811.611.311.010.810.510.210.09.79.59.28.9
1.11015.815.515.215.014.714.414.213.913.713.413.112.912.612.312.111.811.611.311.010.810.510.210.09.79.59.2
1.11216.015.815.515.215.014.714.414.213.913.713.413.112.912.612.312.111.811.611.311.010.810.510.210.09.79.5
1.11416.316.015.815.515.215.014.714.414.213.913.713.413.112.912.612.312.111.811.611.311.010.810.510.210.09.7
1.11616.516.316.015.815.515.215.014.714.414.213.913.713.413.112.912.612.312.111.811.611.311.010.810.510.210.0
1.11816.816.516.316.015.815.515.215.014.714.414.213.913.713.413.112.912.612.312.111.811.611.311.010.810.510.2
1.12017.116.816.516.316.015.815.515.215.014.714.414.213.913.713.413.112.912.612.312.111.811.611.311.010.810.5
1.12217.317.116.816.516.316.015.815.515.215.014.714.414.213.913.713.413.112.912.612.312.111.811.611.311.010.8
1.12417.617.317.116.816.516.316.015.815.515.215.014.714.414.213.913.713.413.112.912.612.312.111.811.611.311.0
1.12617.917.617.317.116.816.516.316.015.815.515.215.014.714.414.213.913.713.413.112.912.612.312.111.811.611.3
1.12818.117.917.617.317.116.816.516.316.015.815.515.215.014.714.414.213.913.713.413.112.912.612.312.111.811.6
1.13018.418.117.917.617.317.116.816.516.316.015.815.515.215.014.714.414.213.913.713.413.112.912.612.312.111.8

If you’re looking to increase the ABV of your beer, check out our guide to increasing ABV using non-malt adjuncts!

Disclaimer: The formula, ABV calculators, and ABV chart contained in this article is intended to be used for estimation purposes only and may not provide accurate results. We cannot guarantee of accuracy of your ABV calculations!

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