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Beer ABV Calculator

Calculate alcohol content from gravity readings

ABV

5.25%

Attenuation

80%

Calories/12oz

112

Before fermentation (typical: 1.030–1.120)

After fermentation (typical: 1.005–1.020)

Alcohol by Volume

5.25%

ABV

ABW

4.17%

by weight

Attenuation

80%

apparent

Calories

112

per 12 oz

Residual Sugar

2.5°P

Plato

ABV Classification

Session
< 4%
Standard
4-6%
Strong
6-8%
Imperial
8%+
5.25% ABV35%

Understanding Results

ABV vs ABW

ABW is ~20% lower since alcohol is lighter than water.

Attenuation

75-80% is typical for most ale yeasts.

Residual Sugar

Lower FG = drier beer, higher FG = sweeter/fuller body.

ABV Formula

ABV = (OG - FG) × 131.25

Standard homebrewing formula. For beers over 6% ABV, more accurate formulas exist.

What You'll Need

Northern Brewer Brew Share Enjoy Homebrew Starter Kit

Northern Brewer Brew Share Enjoy Homebrew Starter Kit

$80-$1204.5
View on Amazon
Brewer's Elite Triple Scale Hydrometer + Test Jar

Brewer's Elite Triple Scale Hydrometer + Test Jar

$12-$184.5
View on Amazon
FastRack Bottle Drying Tree 45-Bottle + Drip Tray

FastRack Bottle Drying Tree 45-Bottle + Drip Tray

$25-$354.6
View on Amazon
Northern Brewer Brew Share Enjoy Homebrew Starter Kit

Northern Brewer Brew Share Enjoy Homebrew Starter Kit

$80-$1204.5
View on Amazon
Brewer's Elite Triple Scale Hydrometer + Test Jar

Brewer's Elite Triple Scale Hydrometer + Test Jar

$12-$184.5
View on Amazon
FastRack Bottle Drying Tree 45-Bottle + Drip Tray

FastRack Bottle Drying Tree 45-Bottle + Drip Tray

$25-$354.6
View on Amazon

As an Amazon Associate, we earn from qualifying purchases.

Example Calculations

1Pale Ale (OG 1.050, FG 1.010)

Inputs

Original Gravity (OG)1.050
Final Gravity (FG)1.010

Result

ABV5.25%
ABW (by weight)4.17%
Attenuation80.0%
Calories (12 oz)155
Residual Sugar2.5 Plato

ABV = (1.050 - 1.010) × 131.25 = 0.040 × 131.25 = 5.25%. ABW = 5.25 × 0.79336 = 4.17%. Attenuation = (0.040 / 0.050) × 100 = 80.0%. Calories = (1881.22 × 1.010 × 0.040) + (3.55 × 10) = 76.0 + 35.5 = ~155.

2IPA (OG 1.065, FG 1.012)

Inputs

Original Gravity (OG)1.065
Final Gravity (FG)1.012

Result

ABV6.95%
ABW (by weight)5.52%
Attenuation81.5%
Calories (12 oz)193
Residual Sugar3.0 Plato

ABV = (1.065 - 1.012) × 131.25 = 0.053 × 131.25 = 6.96% (rounded to 6.95%). ABW = 6.95 × 0.79336 = 5.51%. Attenuation = (0.053 / 0.065) × 100 = 81.5%. Calories = (1881.22 × 1.012 × 0.053) + (3.55 × 12) = 100.9 + 42.6 = ~194.

Frequently Asked Questions

Q

How is ABV calculated from gravity?

ABV is calculated using the formula: ABV = (Original Gravity - Final Gravity) × 131.25. This measures how much sugar was converted to alcohol during fermentation.

  • The simple formula (OG – FG) × 131.25 is accurate within ±0.2% ABV for beers under 6%
  • For high-gravity beers (above 8% ABV), use the alternate formula: ABV = (76.08 × (OG – FG) / (1.775 – OG)) × (FG / 0.794)
  • Take your OG reading after the boil is complete and the wort is cooled to 60–70°F
  • Take FG readings on 2 consecutive days; if identical, fermentation is complete
Q

What is original gravity (OG)?

Original gravity is the specific gravity of your wort before fermentation begins. It indicates the amount of fermentable sugars present. Typical range is 1.030-1.120.

  • Light lagers and session beers: OG 1.030–1.045 (target 3–4.5% ABV)
  • Pale ales and ambers: OG 1.045–1.060 (target 4.5–6% ABV)
  • IPAs and stouts: OG 1.060–1.075 (target 6–7.5% ABV)
  • Imperial/double styles: OG 1.075–1.120 (target 7.5–12%+ ABV)
  • A refractometer ($20–$35) needs only 2–3 drops of wort vs a full test jar for a hydrometer
Beer StyleTypical OGTypical FGExpected ABV
Light Lager1.030–1.0401.004–1.0083.0–4.2%
Pale Ale1.045–1.0601.008–1.0144.5–6.0%
IPA1.060–1.0751.010–1.0156.0–7.5%
Stout1.060–1.0801.012–1.0205.5–8.0%
Imperial Stout1.080–1.1201.015–1.0258.0–12.0%
Q

What is final gravity (FG)?

Final gravity is the specific gravity after fermentation completes. Lower FG means more sugars were converted to alcohol. Typical range is 1.005-1.020.

  • FG below 1.005: very dry finish, common in Belgian tripels and brut IPAs
  • FG 1.008–1.014: balanced, moderate body, typical of most ales and lagers
  • FG 1.015–1.025: sweet, full-bodied, common in milk stouts and scotch ales
  • A stuck fermentation (FG stays high) is often caused by fermentation temperature below 60°F or low yeast pitch rate
  • If using a refractometer for FG, apply a correction factor since alcohol skews Brix readings by 3–5 points
Q

What is attenuation?

Attenuation is the percentage of sugars converted to alcohol by yeast. Higher attenuation (75-85%) produces drier, more alcoholic beer. Lower attenuation leaves more residual sweetness.

  • American ale yeasts (US-05, WLP001): 73–80% apparent attenuation, clean and neutral
  • Belgian yeasts (WLP530, T-58): 78–85% attenuation, very dry with spicy/fruity esters
  • English ale yeasts (WLP002, S-04): 63–75% attenuation, sweeter and more malty finish
  • Lager yeasts (W-34/70): 77–83% attenuation, clean and crisp
  • Mashing at 148–150°F increases fermentability (drier beer); 154–158°F leaves more unfermentable sugars (sweeter)

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Last Updated: Mar 26, 2026

This calculator is provided for informational and educational purposes only. Results are estimates and should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on calculator results.

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