What is a Standard Drink in the USA?

January 1, 2026 •

2 min read

According to the Centers for Disease Control and Prevention (CDC), a standard drink in the United States contains approximately 14 grams or 0.6 fluid ounces of pure alcohol. This precise measurement helps quantify alcohol intake for health and safety purposes, regardless of the type of beverage. Understanding this definition is crucial for responsible consumption and adhering to recommended guidelines.

Quick Summary

A standard drink in the United States contains 14 grams of pure alcohol, though specific beverage sizes differ based on alcohol content. The definition is used by health experts to provide guidance and compare consumption across different types of alcoholic beverages.

Key Points

Definition: A standard drink in the USA contains 0.6 fluid ounces (14 grams) of pure alcohol, as defined by health authorities.
Equivalents: One standard drink is a 12 oz regular beer (5% ABV), a 5 oz glass of wine (12% ABV), or a 1.5 oz shot of 80-proof liquor (40% ABV).
Concentration Matters: The volume of a beverage changes based on its alcohol percentage (ABV), even if the total amount of pure alcohol remains the same.
Serving vs. Standard: Customary serving sizes often exceed the official standard drink size, especially in mixed drinks or larger wine glasses.
Calculation: To find the number of standard drinks, multiply the beverage's volume in ounces by its ABV, then divide by 0.6.
Health Context: Understanding standard drink sizes is vital for following health guidelines and practicing moderate alcohol consumption.

What Defines a Standard Drink?

For public health and safety, the U.S. government, through agencies like the National Institute on Alcohol Abuse and Alcoholism (NIAAA) and the CDC, defines a standard drink based on its pure alcohol content, not the container size. This provides a consistent benchmark for understanding how much alcohol is being consumed. A single standard drink in the USA consistently contains 0.6 fluid ounces, or 14 grams, of pure ethanol. This definition is vital because it is the amount of alcohol itself, not the type of drink, that primarily affects a person's body and blood alcohol concentration (BAC).

The Variety of Standard Drink Equivalents

Due to varying Alcohol by Volume (ABV) percentages, the volume of a beverage can be very different while still containing the same amount of pure alcohol. A 12-ounce can of beer is equivalent to a much smaller glass of wine or a single shot of spirits because the concentration determines the portion size. A stronger craft beer will have a higher ABV and thus contain more than one standard drink in a 12-ounce serving. The same logic applies to wine with a higher ABV.

Common Examples of a Standard Drink

Here are common examples of one standard drink based on average ABV:

Regular Beer: 12 ounces at 5% ABV.
Wine: 5 ounces at 12% ABV.
Distilled Spirits: 1.5 ounces of 80-proof (40% ABV) liquor.
Malt Liquor: 8 ounces at 7% ABV.

Why Portion Size Awareness is Important

Serving sizes often exceed the official standard drink size. A typical wine glass pour or a mixed drink may contain more than one standard drink, leading to faster intoxication. Awareness of a beverage's ABV and measuring drinks is crucial for monitoring consumption.

Comparing Standard Drink Volumes Across Beverages

This table illustrates how volume varies for one standard drink across different beverage types:


Beverage Type	Standard Serving Size (US)	Approximate ABV	Volume of Pure Alcohol
Regular Beer	12 fl oz	5%	0.6 fl oz
Malt Liquor	8 fl oz	7%	0.56 fl oz
Table Wine	5 fl oz	12%	0.6 fl oz
Distilled Spirits (80 Proof)	1.5 fl oz	40%	0.6 fl oz

Understanding Alcohol Percentage and Proof

ABV indicates a beverage's strength. Proof, used for spirits, is double the ABV. For example, 40% ABV is 80 proof. Knowing these values helps calculate standard drinks, especially with higher ABV craft beverages. The standard drink equivalents are based on common ABV levels.

Calculating Standard Drinks

To calculate the number of standard drinks, multiply the drink's volume in ounces by its ABV percentage, then divide by 0.6. For example, a 16-ounce beer with 7% ABV is approximately 1.87 standard drinks. This calculation helps track intake.

Conclusion

A standard drink in the USA is defined by federal health agencies as 0.6 fluid ounces (14 grams) of pure ethanol. The physical volume of a standard drink varies by alcohol concentration. Understanding these equivalents for beer, wine, and spirits is essential for monitoring consumption, adhering to health guidelines, and practicing responsible drinking.

For further information on standard drink equivalents, you can reference the official CDC resource.

Frequently Asked Questions

In the USA, a standard drink contains 0.6 fluid ounces or 14 grams of pure alcohol (ethanol).

A regular 12 oz can of beer with a 5% ABV is considered one standard drink. However, many craft beers and higher-ABV selections contain more than one standard drink per can.

Not always. While 5 ounces of 12% ABV wine is one standard drink, many restaurant pours are larger and can contain 1.5 or more standard drinks.

ABV (Alcohol by Volume) is the percentage of pure alcohol in a beverage. Proof, used mainly for spirits, is double the ABV. For example, 40% ABV is 80 proof.

Knowing the standard drink definition is important for tracking alcohol intake, following health guidelines for moderate consumption, and understanding the potential health risks associated with drinking.

Mixed drinks often contain more than one standard drink. For example, a Long Island Iced Tea can have four or more standard servings of liquor.

Reliable information can be found from public health organizations such as the Centers for Disease Control and Prevention (CDC) and the National Institute on Alcohol Abuse and Alcoholism (NIAAA).