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ABV Calculator and Formula: How to Calculate ABV

By
Brad Johnson
Table of Contents

Do you have a passion for brewing and want to sell your drinks in different types of marketplaces? Or maybe you just want to learn the essentials of home brewing? In either case, it’s useful to know how to calculate ABV

Alcohol by volume, or ABV, is the percentage of a drink’s volume that is pure alcohol. This number indicates the alcohol strength of a drink, and is used in part for cocktail recipe costing

Once you have a formula that works for you, the rest is simple. Keep reading for our ABV calculator and formula that you can utilize today. 

How To Calculate ABV: ABV Formula

Calculating ABV is much simpler than it may sound. Still, it helps to understand why we use it in the first place, and why the standard ABV calculation differs from the one for wine alcohol content.

In order to create alcohol, the sugar in a liquid must be converted to ethanol. This is done by adding yeast and the liquid to a fermentation vessel, like an oak barrel or stainless steel tank.

Yeast breaks down the sugar molecules into pyruvate molecules, which form pyruvic acid. The pyruvic acid molecules are then broken down into ethanol and 2CO2, or carbon dioxide.

To get the right ABV, you need to measure your liquid’s original gravity (OG) before fermentation. You can do this with a hydrometer, which is a tool that measures the gravity of a liquid. After taking note of your liquid’s OG, you can continue with fermentation. 

When fermentation is complete, measure the final gravity (FG) of your alcohol. This shows how much the density has changed and is crucial to get an accurate ABV. 

With these two numbers and the right formula, you can calculate your drink’s ABV. Here is the basic ABV formula: 

(Original gravity - final gravity) x 131.25 = alcohol by volume, as a percentage

Here is an example of what a real calculation could look like: 

(2.075 - 2.015) x 131.25 = 7.88% ABV (rounded up)

A beer with this ABV would be on the higher side, but it’s no less possible. If you’re wondering why brewers use 131.25, we’ll offer a simplified explanation.

This number comes from a chemistry equation that includes the density of ethanol and the number of ethanol grams generated per gram of carbon dioxide released. Brewers have been using this same formula for centuries, so 131.25 has become a reliable number for determining general beer ABVs. 

Even if you love math, there’s only so much manual calculation one person can do in a day. That’s why our cutting-edge bar inventory software, BinWise, can do the heavy lifting for you. Instead of slogging through inventory counts, submitting paper purchase orders, and dealing with manual data entry, use our perpetual inventory system

We even have BinScan, our inventory scanning app that scans over 100 bottles per minute. Book a demo today to see how BinWise can improve your business’s daily profitability. 

ABV Calculator

Whether you’re making your own drinks or want to help a friend with theirs, having an ABV calculator is handy. It shows you how strong different types of alcohol are and can help you pick the best alcohol for shots

Measuring Specific Gravity of a Liquid

The conversion of sugar to ethanol is what gives us the opportunity to calculate alcohol by volume, or ABV. In order to calculate ABV, you need two specific numbers: your wort’s original gravity (OG) and its final gravity (FG). If you aren’t familiar with the term wort, it’s the sweet liquid produced by combining mashed grains with hot water.

Liquid gravity is used as a measurement for ABV because it indicates how much the density of a liquid has changed. Density changes show how much the alcohol content has changed, hence the importance of alcohol by volume. The smaller change in density, the higher the ABV. The greater change in density, the lower the ABV.

We researched some of the easiest ABV calculators so you can get to work right away. Here are some free online ABV calculators: 

Home Brew Supply

As the name suggests, Home Brew Supply is a company that offers equipment, ingredients, and recipes for home brewers. Their website provides a simple plug-and-play calculator that automatically updates when you change the data.

You can calculate by specific gravity (SG) or Plato, the measurement of dissolved solids in a wort. Most homebrewers will only need SG. 

Brewer’s Friend

Brewer’s Friend is a comprehensive eCommerce store, forum, and online toolkit dedicated to helping independent brewers. Their site features a calculator that’s similar to Home Brew Supply and others’.

Simply choose your gravity unit, add your OG and FG, choose a standard or alternate equation, and you’re set. The calculator will also show the number of calories that would be in a 12-ounce bottle of your drink. 

Hopsteiner

Hopsteiner is a New York-based hops company that’s been growing hops on local farms for over 150 years. They also have a handy ABV calculator that’s free to use. 

All you need to do is enter your wort’s OG and FG, and choose your preferred gravity unit. The calculator will take care of the rest! 

MeadMakr

If mead is your alcoholic beverage of choice, there’s one website that stands out. That’s MeadMakr, and their ABV calculator is specifically designed for mead brewers. 

You can calculate via specific gravity (SG) or Brix, instead of Plato. Plato measures the weight of the solids dissolved in water, whereas Brix measures the weight of sucrose dissolved in water.

Brix is more useful when measuring mead, because mead is made with honey. Because honey has substantial sucrose content, brewers need a way to measure how much sucrose has dissolved in the mead. This makes it easier to determine its ABV. 

Homebrew Academy

Homebrew Academy offers courses on how to brew your own alcoholic beverages at home. Their minimalist site also includes an ABV calculator, though it only includes measurement via SG. 

If you need to quickly determine your drink’s ABV, this website is a great resource for you. Enter your OG and FG and you’ll have your ABV in seconds. The calculator also provides your drink’s calorie count, apparent attenuation, real attenuation, and alcohol by weight (ABW). 

Beer ABV Calculator

Beer is one of the most popular alcoholic beverages in America. About two-thirds of American adults drink alcohol, roughly 42% of whom prefer beer. Americans consume about 40 gallons of beer per person annually. Viewed another way, this is the equivalent of pouring beer into 12-ounce servings a little more than once per day.

If you’re preparing to brew your own and need a reliable beer ABV calculator, check out the below options: 

MoreBeer

MoreBeer is one of the leading beer equipment, recipe, and starter kit websites for home beer brewing. From mash paddles and hydrometers to kettles and more, you’ve got everything you need to make great beer. 

They also have a simple beer ABV calculator. Add your OG and FG, select your unit of measurement, and you’re all set. The only point of note here is that MoreBeer’s calculator doesn’t provide additional information; only ABV. 

Craft Beer & Brewing 

As you may have guessed, Craft Beer & Brewing is a website dedicated to all aspects of craft beer creation. From the ingredients that go into your mash and wort to the tools necessary to brew beer, this company has it all.

One of the free tools they offer is a beer ABV calculator, which is just as easy to use as those on other sites. Choose between SG or Plato measurement, add your OG and FG, and get your results. The Craft Beer & Brewing calculator provides both the ABV and ABW. 

Wine ABV Calculator

If you want to calculate ABV for common wine bottle sizes, you should first know that this formula isn’t the same as beer. On average, beer is about half to one-third of wine ABV levels. This means that you need a different formula to calculate wine ABV. 

Since most people don’t make their own wine, a wine ABV calculator is harder to come by. You can still easily calculate wine ABV with the right approach. The formula below can be used as a standard wine ABV calculator: 

(Starting fermented units - ending fermented units) / 7.4 = wine ABV, as a percentage

Here’s an example of what your wine ABV could look like: 

(1115 starting units - 1015 ending units) / 7.4 = 13.51% ABV

Cocktail ABV Calculator

Though there may not be a cocktail ABV calculator that suits all circumstances, there are ways to determine your drink’s alcohol content. The tricky thing about popular cocktail recipes is they’re mixed drinks, meaning your final ABV depends on multiple factors. 

Thankfully there’s a simple formula you can use as a makeshift cocktail ABV calculator. It involves calculating the alcohol content of each alcoholic beverage in your drink. Take a look below: 

(Ounces of first alcohol x first alcohol’s ABV = amount) + (Ounces of second alcohol x second alcohol’s ABV = amount) / (Total volume of each drink ingredient) = the cocktail’s ABV

We know this looks a little overwhelming, but don’t worry; it’s simpler than it appears. Here’s a real-life example for a Cosmopolitan, one of many happy hour drinks

(0.5 oz orange liqueur x 0.30 ABV = 0.15) + (1.5 oz vodka x 0.40 ABV = 0.60) / (0.5 oz cranberry juice + 0.25 oz lime juice + 0.5 oz orange liqueur + 1.5 oz vodka = 2.75 total oz) = 0.27, or 27% ABV

Here is the simplified version: 

0.15 + 0.60 / 2.75 = 27%

As you can see, the ABV you’ll get depends on the ingredients in popular cocktails, their alcohol strength, and the liquid volume of your drink. This cocktail ABV formula can be expanded for as many kinds of alcohol or additional liquid ingredients are in your recipe. 

ABV To Proof Calculator

If you need the proof of a drink, in most cases you don’t need a full-blown ABV to proof calculator. This is because proof is close to two times the ABV of any drink. 

Instead of looking online for a calculator, you can perform this simple formula yourself: 

ABV of drink x 1.75 = proof of drink

Here’s a quick example: 

35 ABV x 1.75 = 61.25

That’s all there is to converting ABV to proof! Some people use 2 instead of 1.75 because in many cases proof is nearly twice the ABV amount, but 1.75 is usually more accurate. 

Frequently Asked Questions About ABV Calculator

Whether you love math or dislike it, there’s no doubt about one thing. Determining ABV requires formulas galore, and they take some time to memorize.

If you still have questions about ABV or are learning about it for the first time, you’re in the right place. We researched frequently asked questions about ABV calculation so you don’t need to. Take a look at our answers below: 

How do you calculate ABV?

ABV is easy to calculate and can be done with the following formula:

(Original gravity - final gravity) x 131.25 = ABV percentage

Original gravity is your liquid’s density before fermentation, final gravity is the density after fermentation, and multiplying by 131.25 handles the rest of the chemistry. 

What is ABV calculator?

An ABV calculator is used to determine how much of a drink is pure alcohol. ABV is useful to know because it reveals how strong an alcoholic beverage is, and what kinds of cocktails it’s suited for. 

How do you calculate ABV of Plato?

In simple terms, every 1°P (Plato) is equivalent to roughly 0.40% ABV generated. So about 10°P will generate around 4% ABV. 

There are other more complex formulas out there that get into the nuances of Plato-to-ABV calculation. However, for most people brewing their own drinks at home, this is a general, reliable formula. 

ABVery Excited to Try This Drink

Adding ABV calculations to your bar staff toolbelt is a great move. It makes you aware of specific beverages’ intensity, which drinks work for summer cocktails or winter cocktails, and more. By using the formulas in this blog post, you’ll never be at a loss as to how strong a given drink is.