What is a Standard Drink? Complete Alcohol Equivalency Guide
Understanding standard drinks is essential for tracking alcohol consumption and calculating BAC accurately
Standard Drink Definition
One standard drink contains 14 grams (0.6 ounces) of pure alcohol. This is the amount of alcohol in:
- • 12 oz of regular beer (5% ABV)
- • 5 oz of wine (12% ABV)
- • 1.5 oz of distilled spirits (40% ABV)
Why Standard Drinks Matter
When someone asks "How much did you drink?" most people answer with the number of containers—"I had 3 beers" or "2 glasses of wine." But not all drinks are created equal.
A 12 oz beer at 5% alcohol is not the same as a 16 oz craft IPA at 8% alcohol, even though both are "one beer." The standard drink system solves this problem by measuring alcohol by actual ethanol content, not container size.
Understanding standard drinks helps you:
- Track your alcohol consumption accurately
- Use BAC calculators correctly (they require standard drink counts)
- Follow health guidelines (CDC recommends ≤1 drink/day for women, ≤2 for men)
- Understand drink equivalency across different beverage types
- Make informed decisions about pacing and limits
Beer: Standard Drink Conversions
Regular Beer (5% ABV)
| Serving Size | Standard Drinks | Examples |
|---|---|---|
| 12 oz (1 can/bottle) | 1.0 | Bud Light, Coors, Miller Lite |
| 16 oz (1 pint) | 1.3 | Draft beer at bars |
| 22 oz (bomber) | 1.8 | Large bottle beer |
| 40 oz (forty) | 3.3 | Malt liquor |
Craft Beer & IPAs (7-10% ABV)
Craft beers, especially IPAs, double IPAs, and imperial stouts, often have significantly higher alcohol content than regular beer. This is where people commonly underestimate their intake.
| Beer Type | ABV | 12 oz = | 16 oz Pint = |
|---|---|---|---|
| Regular Beer | 5% | 1.0 drinks | 1.3 drinks |
| Craft IPA | 7% | 1.4 drinks | 1.9 drinks |
| Double IPA | 9% | 1.8 drinks | 2.4 drinks |
| Imperial Stout | 10% | 2.0 drinks | 2.7 drinks |
Critical Mistake: If you drink 3 pints of 8% craft beer, you've consumed ~6.4 standard drinks, not 3. This is equivalent to 6-7 regular beers and will produce a significantly higher BAC than expected.
Wine: Standard Drink Conversions
Wine by Type (12-15% ABV)
| Wine Type | ABV | 5 oz Glass = | 750ml Bottle = |
|---|---|---|---|
| Light White Wine | 10-11% | 0.8-0.9 drinks | 4.0-4.5 drinks |
| Standard Wine | 12% | 1.0 drinks | 5.0 drinks |
| Red Wine | 13-14% | 1.1-1.2 drinks | 5.4-5.8 drinks |
| High-Alcohol Red | 15% | 1.3 drinks | 6.3 drinks |
| Port/Sherry | 18-20% | 1.5-1.7 drinks | 7.5-8.3 drinks |
Wine Glass Sizes: The Hidden Problem
The "standard" 5 oz wine pour is smaller than most people realize. Restaurant wine glasses often hold 8-12 oz when filled to the rim, and home pours are notoriously generous.
| Pour Size | Standard Drinks (12% wine) | Common Scenario |
|---|---|---|
| 5 oz (standard) | 1.0 | Measured restaurant pour |
| 8 oz (generous) | 1.6 | Typical home pour |
| 10 oz (large) | 2.0 | Full wine glass |
| 12 oz (very large) | 2.4 | Oversized wine glass filled |
⚠️ If you split a bottle of wine (750ml) with someone, you've each consumed approximately 2.5 standard drinks, not "2-3 glasses."
Liquor & Spirits: Standard Drink Conversions
Distilled Spirits (40% ABV / 80 Proof)
| Spirit Type | ABV | 1.5 oz Shot = | 750ml Bottle = |
|---|---|---|---|
| Vodka, Rum, Whiskey | 40% | 1.0 drinks | 17 drinks |
| High-Proof Bourbon | 50% | 1.25 drinks | 21 drinks |
| Everclear | 95% | 2.4 drinks | 40 drinks |
| Liqueur (Baileys) | 17% | 0.4 drinks | 7 drinks |
Mixed Drinks & Cocktails
Cocktails are the most difficult to estimate because recipes vary widely and bartenders often pour generously. Here are common approximations:
| Cocktail | Typical Recipe | Standard Drinks |
|---|---|---|
| Vodka Soda | 1.5 oz vodka | 1.0 |
| Margarita | 2 oz tequila, 1 oz Cointreau | 1.7-2.0 |
| Old Fashioned | 2 oz whiskey | 1.3 |
| Martini | 2.5 oz gin/vodka | 1.7 |
| Long Island Iced Tea | 5 spirits (0.5 oz each) | 2.5-4.0 |
| Mai Tai | 2 oz rum, 0.5 oz Curaçao | 1.5-2.0 |
| Mojito | 2 oz rum | 1.3 |
| Whiskey Sour | 2 oz whiskey | 1.3 |
Cocktail Warning
Many restaurant and bar cocktails use doubles (2 oz shots) instead of standard 1.5 oz pours. A "double vodka tonic" is actually 2.7 standard drinks, not 1. Always ask your bartender about pour sizes.
How to Calculate Standard Drinks
The Formula
Standard Drinks = (Volume in oz × ABV × 0.0295735) ÷ 14
Where:
• Volume = Serving size in fluid ounces
• ABV = Alcohol by volume (as decimal, e.g., 0.12 for 12%)
• 0.0295735 = Conversion factor (oz to grams)
• 14 = Grams of alcohol in one standard drink
Example Calculations
Example 1: 16 oz pint of 7% IPA
Standard Drinks = (16 × 0.07 × 0.0295735) ÷ 14
= (0.0331) ÷ 14
= 1.87 standard drinks
Example 2: 8 oz glass of 14% red wine
Standard Drinks = (8 × 0.14 × 0.0295735) ÷ 14
= (0.0331) ÷ 14
= 1.87 standard drinks
Example 3: 2 oz shot of 50% bourbon
Standard Drinks = (2 × 0.50 × 0.0295735) ÷ 14
= (0.0296) ÷ 14
= 1.27 standard drinks
Quick Reference: Common Mistakes
❌ Mistake: "I had 2 beers" = 2 standard drinks
Reality: If those were 16 oz pints of 7% IPA, you actually consumed ~3.7 standard drinks (nearly double).
❌ Mistake: "I only had 3 glasses of wine"
Reality: If you poured 8 oz glasses of 14% wine, that's ~5 standard drinks, not 3.
❌ Mistake: "One Long Island Iced Tea = 1 drink"
Reality: Most Long Islands contain 2.5-4 oz of liquor, equal to 3-4 standard drinks.
❌ Mistake: "Beer is weaker than wine or liquor"
Reality: 12 oz beer (5%) = 5 oz wine (12%) = 1.5 oz liquor (40%). All contain 14g of pure alcohol—exactly the same.
Using Standard Drinks with BAC Calculators
When using a BAC calculator, you must input the number of standard drinks, not containers.
Example Scenario:
You had:
- 2 pints of 8% craft beer (16 oz each)
- 1 margarita
Correct calculation:
- 2 pints × 2.1 drinks/pint = 4.2 standard drinks
- 1 margarita = 1.8 standard drinks
- Total: 6.0 standard drinks
If you incorrectly entered "3 drinks" (2 beers + 1 margarita) into the calculator, it would significantly underestimate your BAC by 50%.
International Standard Drink Differences
The 14-gram definition is used in the United States. Other countries use different standards:
| Country | Grams of Alcohol | Comparison to US |
|---|---|---|
| United States | 14g | — |
| United Kingdom | 8g (1 unit) | 1 US drink = 1.75 UK units |
| Australia | 10g | 1 US drink = 1.4 AU drinks |
| Canada | 13.6g | Nearly identical |
| Japan | 19.75g | 1 US drink = 0.71 JP drinks |
Health Guidelines and Standard Drinks
According to the CDC and NIAAA (National Institute on Alcohol Abuse and Alcoholism):
Moderate Drinking
- Women: ≤1 standard drink per day
- Men: ≤2 standard drinks per day
Binge Drinking (NIAAA Definition)
- Women: ≥4 standard drinks within 2 hours
- Men: ≥5 standard drinks within 2 hours
This typically raises BAC to 0.08% or higher.
Heavy Drinking
- Women: ≥8 standard drinks per week
- Men: ≥15 standard drinks per week
The Bottom Line
Key Takeaways
- •One standard drink = 14 grams of pure alcohol
- •12 oz beer (5%) = 5 oz wine (12%) = 1.5 oz liquor (40%) = 1 standard drink
- •Craft beers, large wine pours, and cocktails often contain 2-4 standard drinks each
- •Always use standard drink counts when calculating BAC, not container counts
- •When in doubt, overestimate your drink count for safety
Calculate Your BAC Accurately
Now that you understand standard drinks, use our BAC calculator to accurately estimate your blood alcohol concentration. Remember to convert your drinks to standard units first!
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Important Disclaimer
This article is for educational purposes only and does not constitute medical, legal, or professional advice. Standard drink calculations are approximations. Individual metabolism, health conditions, and other factors affect how alcohol impacts your body. Never use standard drink estimates to determine if you are safe to drive—the only safe BAC for driving is 0.00%. When in doubt, do not drive.