Omni calculator
Last updated:

ABV Calculator (Alcohol by Volume)

Table of contents

What is alcohol by volume?Calculating ABV from specific gravityDifference between ABV, ABW and proofUsing our alcohol by volume calculator – an exampleWhat is alcohol?Alcohol formulaAlcohol factsMyths about alcoholHistory of alcoholFAQs

If you want to calculate the alcohol content of your homebrew beer 🍺, this ABV calculator (alcohol by volume calculator) is the perfect tool for you. It will help you estimate the percentage of alcohol in any liquor based on its initial and final specific gravity. Specific gravity is explained in our specific gravity calculator.

In the article below, you can read about what alcohol is, alcohol facts, myths about alcohol, and the history of alcohol. Moreover, you can find information about calculating ABV from specific gravity and discover the alcohol formula. Use this beer ABV calculator wisely, and try not to fall into addiction! 😀

This specific gravity calculator and the ABV formula are based on the results from the research paper Examination of the Relationships Between Original, Real and Apparent Extracts, and Alcohol in Pilot Plant and Commercially Produced Beers, published by Anthony J. Cutaia, Anna-Jean Reid and R. Alex Speers in the Journal of the Institute of Brewing.

What is alcohol by volume?

ABV is an abbreviation for alcohol by volume. This unit is a standard measure of how much alcohol (ethanol) is contained in a given volume of an alcoholic beverage. It is expressed as a volume percent. By definition, this is the number of milliliters of pure ethanol present in 100 mL of a solution at 20 °C (68 °F).

The ABV standard is commonly used worldwide. In some countries, e.g., France, the term alcohol by volume is often replaced by degrees Gay-Lussac (thanks to the French chemist Joseph Louis Gay-Lussac). These two scales differ slightly: Gay-Lussac uses the value of 15 °C (59 °F) for temperature (instead of 20 °C).

Calculating ABV from specific gravity

The standard method of estimating ABV is to use the specific gravity. Specific gravity is the relative density of a liquid compared with the density of water. When fermentation occurs, the specific gravity of the liquid changes. You can monitor this change to find the alcohol content of your home brew.

All formulas for finding the ABV are approximated, as they are found empirically rather than derived. The most recent formula was derived by Cutaia, Reid, and Speers in 2009. The first formula from their research relates the measurements of the alcohol content by weight with the original and apparent extract:

ABW = (0.372 + 0.00357 × OE) × (OE - AE)


  • ABW — Alcohol by weight, measured in percent;
  • OE — Original extract (before fermentation), measured in Plato degrees (°P); and
  • AE — Apparent extract (after fermentation).

From this alcohol formula, they derived an equation for alcohol by volume:

ABV = ABW × (1.308 × 10-5 + 3.868 × 10-3 × AE + 1.275 × 10-5 × AE2 + 6.3 × 10-8 × AE3 + 1) / 0.7907

The last thing our beer calculator does is find the exact amount of alcohol in a given volume of alcoholic beverage. For example, you can determine the volume of alcohol in a 500 ml bottle of 4.5% beer. If you are interested in determining this value, use this equation:

alcohol volume = total volume × ABV

Are you a driver who often consumes alcohol and would love to monitor your alcohol intake? Our alcohol unit calculator is just the tool for you.

Difference between ABV, ABW and proof

The proof is a different measure of an alcoholic beverage. Its origins date back to 16th century England, where liquors were taxed based on their alcohol content. They were tested in the following way: a pellet of gunpowder was soaked in a spirit, and if it could still burn afterward, the spirit was deemed above proof and taxed higher than ordinary.

In 1816, the gunpowder test was replaced with a specific gravity test. Since then, the main measure of alcohol content has been ABV (alcohol by volume) or ABW (alcohol by weight). Still, you can find the equivalent of proof in ABV:

  • In the US, 'proof' is equal to twice the measure in ABV. For example, alcohol that is 100 proof has 50% ABV.
  • In the UK, proof is defined as: "a quantity of 100 degrees proof liquor has the same weight as 12/13 of the same volume of pure water at 51 °F." Hence, 100-proof alcohol has 57.15% ABV.

Using our alcohol by volume calculator – an example

Let's assume you are brewing your own beer. What do you need to do to determine the volume of alcohol in one 330 ml bottle?

  1. Begin by calibrating your hydrometer. Check whether it's reading for clear water is equal to 1. If not, you will have to adjust all consecutive readings.

  2. Take a hydrometer reading of your homebrew before fermentation begins. Let's assume this value – the original specific gravity – is equal to 1.060.

  3. Take a second hydrometer reading when your beer is ready to drink. In this example, we will assume the final specific gravity equal to 1.015.

  4. Change the units of the first two variables of our calculator – instead of showing Plato's degrees, they will now show the specific gravity.

  5. Input the hydrometer readings into the calculator. You can change the units again to see that OE = 14.740 °P and that AE = 3.825 °P.

  6. Our beer calculator will automatically find the value of ABV. In this case, the ABV of your beer is equal to 5.95%.

  7. Once you have calculated the ABV, you can find the volume of alcohol in your beer by multiplying it by the total volume of homebrew in a bottle:

    5.95% × 330 = 19.63 ml

What is alcohol?

Alcohol (ethanol or ethyl alcohol) is everyone's favorite chemical compound, found in beer, wine, vodka, and spirits. Our feelings after drinking are determined by the concentration of this small chemical molecule in our body. Consumed in reasonable amounts, they cause pleasure, while in excessive volume — drunkenness.

Alcohol is formed when yeast ferments (breaks down without oxygen) the sugars in different food. For example, wine is made from the sugar in grapes, beer from the sugar in malted barley, cider from the sugar in apples, and vodka from the sugar in potatoes, barley, or other plants. Fermented drinks (beer or wine) contain from 2% to 20% of alcohol. Distilled drinks or liquors contain from 40% to 50% (or even more) of alcohol. The usual alcohol content for each is:

  • Beer 2-6%
  • Cider 4-8%
  • Wine 8-20%
  • Tequila 40%
  • Rum 40% or greater
  • Brandy 40% or greater
  • Gin 40-47%
  • Whiskey 40-50%
  • Vodka 40-50%
  • Liqueurs 15-60%

Alcohol is classified as a sedative hypnotic drug. It means that it acts to depress the central nervous system at high doses. On the other hand, in lower doses, it can act as a stimulant, inducing feelings of euphoria and increasing talkativeness. Keep in mind that alcohol overdose may lead to drowsiness, respiratory depression (slow and shallow breathing that can stop entirely), falling into a coma, or even death. In fact, alcohol has negative effects on every organ in the body. These effects depend on the blood alcohol concentration (BAC) over time. Blood alcohol concentration is further explained in our BAC calculator

Alcohol formula

From a chemical point of view, alcohol is an organic compound. Alcohols are not limited to ethanol and are characterized by one or more hydroxyl (-OH) groups, which are attached to a carbon atom of an alkyl group. Alcohols may be considered organic derivatives of water (H₂O) in which an alkyl group has replaced one of the hydrogen atoms. For example, in ethanol (or ethyl alcohol), the alkyl group is the ethyl group, −CH₂CH₃.

Alcohols are among the most common organic compounds. They are used as sweeteners and in perfume production. Probably the two best-known alcohols are ethanol and methanol. The first one is commonly used for the production of toiletries, pharmaceuticals, fuels, and of course, alcoholic beverages. The second one is used as a raw material for manufacturing formaldehyde and special resins in special fuels, antifreeze, and cleaning materials.

Alcohol facts

Take a look at a few curious facts associated with alcohol and drinking.

  1. It only takes 6 minutes for brain cells to react to alcohol.

  2. The only type of alcohol that humans can drink without causing severe damage to the organism is ethanol or ethyl alcohol. They are widely used in beverages such as wine, beer, spirits, etc.

  3. Alcohol is among the most commonly misused addictive substances. About 13% of American adults meet the criteria for alcohol use disorder (AUD). That is 1 in 8 adults😲!

  4. Alcohol can cause a wide variety of effects. It triggers the release of dopamine – a neurotransmitter associated with pleasure and satisfaction.

  5. According to the 2015 National Survey on Drug Use and Health, 86.4% of adults have drunk alcohol at some point in their lifetime.

  6. Alcohol is a depressant. This means that it slows down the activity of the brain.

  7. Alcohol is processed in the liver, where enzymes help break down ethanol into acetaldehyde and acetate.

  8. Men are more likely to use alcohol than women.

  9. Women who are dependent on alcohol are 50-100% more likely to die from alcohol-related causes than men who are addicted to alcohol.

  10. Archaeologists found evidence suggesting that builders of the Great Pyramids of Giza were paid in beer.

  11. The effects caused by drinking occur when ethanol enters your bloodstream and passes through the membranes of cells in your brain, heart, and other organs.

  12. Stress relief is another side effect of drinking alcohol. This is caused by an increase in the uptake of the neurotransmitter called GABA. To learn more about what GABA is visit our gabapentin dosage calculator.

Myths about alcohol

After reading these alcohol facts, it's time to bust a few myths that most people still believe. You might be really surprised…

  1. Wine or beer won't make you as drunk as high-volume alcohol. The truth: all types of alcohol contain the same active ingredient, which makes us dizzy. It depends on how much of that particular substance you consume during one sitting.

  2. Drinking is not a problem as long as you can hold your glass. The truth: being able to drink without feeling the effects could be a sign that you are developing alcohol tolerance. Over time, regular alcohol use can lead you to risk for AUD.

  3. Drinking in moderation is always safe. The truth: moderate alcohol consumption may have some health benefits, but it doesn't mean you can always do it without risk. In some situations, you must not drink — e.g., while pregnant or having a liver/pancreatic disease.

  4. Drinking alcohol of unknown origin is safe because alcohol inside is always the same. The truth: homemade or unknown-made alcohol may include contaminated alcohol or even toxic types of alcohol like methanol. You can go blind or even die after drinking it. If you are someone who likes to make your own wine, our so2 wine calculator may interest you.

  5. A cup of coffee will help you sober up. The truth: coffee contains caffeine, which makes you feel more alert and awake. It doesn't help your body process alcohol faster.

History of alcohol

For thousands of years, people have used fermented grain, fruit juice, and honey to make alcohol. Fermented beverages existed in early Egypt and China (there is evidence of an early alcoholic drink from 7000 b.c.e.) In India, an alcoholic beverage called 'sura' (distilled from rice) was in use between 3000-2000 b.c.e.

Several Native American civilizations developed alcoholic beverages in pre-Columbian times. In the Andes region in South America, lots of fermented beverages called 'chicha' were created from corn, grapes, or apples.

In the 16th century, alcohol called 'spirits' was largely used for medical purposes. Later on, in mid-eighteenth century Britain, gin consumption reached 18 million gallons, and alcoholism became widespread. The nineteenth century brought a change in attitudes, and the temperance movement began promoting the moderate use of alcohol. This finally led to a push for total prohibition.

In 1920, the US passed a law prohibiting the manufacture, sale, import, and export of intoxicating liquors. The illegal alcohol trade boomed, and by 1933, the prohibition of alcohol was canceled. Today, estimation shows that 15 million Americans suffer from alcoholism, and 40% of all car accident-related deaths in the US involve alcohol.


How much alcohol is 80% proof?

Alcohol that's 80-proof means it contains 40% pure alcohol (ethanol) by volume. To put it simply, it's very strong. Regular, strong alcoholic beverages like whiskey or vodka are usually around 40% pure alcohol.

Is 100-proof alcohol strong?

Yes, 100-proof alcohol is strong. To give you an idea:

  • Common spirits like vodka and whiskey are typically around 80-proof.
  • Beer usually has a much lower alcohol content, around 10-20 proof.
  • Wine ranges from 20 to 50 proof.

What does 5% alcohol by volume mean?

5% alcohol by volume means that in a given beverage, 5% of the total liquid is pure alcohol (ethanol). This measurement helps you understand the drink's strength or potency. 5% alcohol content is usually typical for beers.

How much is 40% alcohol by volume?

40% alcohol by volume means that in a given beverage, 40% of the liquid is pure alcohol (ethanol). So, a 750ml bottle of a drink labeled as 40% ABV contains 300ml (10 ounces) of alcohol.

How do I convert proof to alcohol percentage?

To convert proof to alcohol percentage, follow these steps:

  1. Check what proof your alcohol is.
  2. Divide the proof by 2 (US).
  3. The result is the percentage of alcohol by volume in your beverage.

Remember, the proof system is common in the United States, while many other countries use the ABV (alcohol by volume) system. Converting between the two is essential to understand the strength of alcoholic drinks.

Beer gravity

Alcohol content

Alcohol volume in your beer

Check out 4 similar drinks calculators 🥤
Alcohol dilutionChilled drinkMolecular SO2...1 more