The guide

What's really in your glass

By GyroscopeUpdated November 14, 20265 sources

A US standard drink holds 14 grams of pure alcohol, the amount in 12 oz of 5% beer, 5 oz of 12% wine or 1.5 oz of 40% spirits. Most real pours are bigger or stronger, so a restaurant glass of wine is about 1.35 drinks and a 16 oz IPA is almost 2. Count by ounces and strength.

Most people count glasses. One glass of wine, one beer, one cocktail, three drinks. It feels fair, because each one arrives as one thing in your hand. But the glass tells you nothing about how much alcohol is in it. Even NIAAA, the federal alcohol research institute, says “many people are surprised to learn what counts as a drink,” and that the standard amounts “may not reflect customary serving sizes.”

Why isn’t a glass one drink?

Ordering a drink is like ordering a “medium” coffee. The name tells you nothing about the size, and it changes from place to place.

Two things set how much alcohol you get, the size of the pour and the strength of what’s in it. A 12 oz bottle of 5% beer is one drink. The same bottle of a 10% craft beer is two, as NIAAA puts it. A light beer at 4.2% still has about 85% of the alcohol of a regular one, which surprises a lot of people who switch to light beer to drink less.

Wine is where most people undercount. The standard 5 oz pour assumes 12% wine. A lot of red wine is 13.5% or more, and a lot of glasses hold 6 oz or more, so the “one glass” with dinner is often 1.35 drinks, and a generous 9 oz pour of 13.5% wine is two.

How do you count a drink?

Every drink comes down to one line of math. Ounces times 29.57 gives you milliliters. Times the ABV gives you milliliters of pure alcohol. Times 0.789, the weight of a milliliter of alcohol, gives you grams. Divide by 14 and you have US drinks.

For a 6 oz pour of 13.5% red wine, that’s 177 mL, which holds 24 mL of alcohol, which weighs 18.9 g. Divided by 14, it’s 1.35 US drinks.

Real pours, in US standard drinks

112 oz beer12 oz, 5%

15 oz wine5 oz, 12%

1A shot1.5 oz, 40%

1.3316 oz pint16 oz, 5%

1.356 oz pour6 oz, 13.5%

1.916 oz IPA16 oz, 7%

29 oz pour9 oz, 13.5%

5.7A bottle750 mL, 13.5%

A cocktail is the sum of its pours. Say a margarita has 2 oz of 40% tequila and 1 oz of a 30% orange liqueur. That’s 18.7 g plus 7.0 g, or 1.8 US drinks in one glass. The What’s in your glass calculator does this for any pour, and lets you guess first.

Why does the pour change your whole evening?

Every other number depends on it. The time a drink takes to clear, the part of your night it reaches and where your week sits against the US lines all start from grams.

Here’s how a normal week can drift. Say a woman has one glass of wine on Wednesday, three on Friday and two on Saturday, all 6 oz pours of 13.5% wine. She’d call it six drinks. It’s 8.1 US drinks, which is at NIAAA’s heavy drinking line for women of 8 or more a week. Friday alone is 4.05, at the line of 4 or more on any day. Your week does this for your own nights.

How many calories are in a drink?

Alcohol carries about 7 calories a gram. A US drink’s 14 g is about 100 calories from the alcohol alone, so a bottle of 13.5% wine is about 560.

Beer, wine and mixers add more on top, from their carbs and sugar, and a sweet cocktail can add a lot. The table above counts only the alcohol, so treat it as the floor. If you’re watching your weight, bodyfat.guide covers what those calories do, and tdee.guide gives you a daily number to set them against.

What else is in the glass?

Ethanol is what makes a drink a drink, and it’s what this site counts. The rest is water, sugar, and small amounts of other compounds from fermenting and aging, called congeners. Darker drinks like bourbon carry more of them than clear ones like vodka.

Congeners change how you feel the next day, and not much else. In a 2010 study, 95 heavy drinkers aged 21 to 33 drank either bourbon or vodka on one night, to the same level, and a placebo on another. The bourbon drinkers felt worse the next morning. Their sleep and their next-day attention took the same hit as the vodka drinkers’. Clear drinks and hangovers has the full story.

What does “non-alcoholic” mean on a label?

Under US labeling rules, a “non-alcoholic” beer can have up to 0.5% alcohol. A 12 oz bottle at that limit holds about 1.4 g, a tenth of a US drink, which won’t change your night. Only a beer labeled “alcohol free” has none, and that’s the one to pick if you need zero.

What we left out from the old guide

Gyroscope’s first alcohol guide had a list of cocktails by grams of sugar, notes on sulfites and histamines in wine, and calorie comparisons with juice and milk. We couldn’t find a source that holds up for the sugar list or the wine headache claims, so they’re out. The calorie numbers here are worked out from the grams.