حاسبة المشروبات القياسية

A standard drink is a fixed quantity of pure alcohol, and the point of the unit is that it lets very different drinks be compared. It is also the source of a persistent misunderstanding: a standard drink is not a glass, a bottle or a can. A pint of strong craft beer can contain three standard drinks, which is why people who count glasses routinely underestimate their intake by a factor of two or more.

المعادلة

Standard drinks = volume (mL) x ABV (%) / 100 / mL of pure alcohol per standard drink
US: 17.7 mL (14 g) per standard drink
UK unit: 10 mL (8 g) per unit

• volume = the amount of the drink in millilitres
• ABV = alcohol by volume, the percentage printed on the label
• Countries define the standard differently, which is why the same drink converts to different numbers

US definition from the National Institute on Alcohol Abuse and Alcoholism: 14 grams of pure alcohol. The UK unit is 8 grams. Definitions elsewhere range from about 8 to 20 grams.

What counts as one standard drink

The US equivalents below all contain about 14 grams of pure alcohol. They look nothing alike, which is the point of the unit.

• A 16 fl oz pint of 7 percent IPA contains about 2.2 US standard drinks, not one.
• A generous restaurant pour of wine is often 6 to 9 fl oz, which is 1.2 to 1.8 standard drinks rather than one.
• Home pours of spirits are typically larger than 1.5 fl oz, frequently by a factor of two.

Elimination is not exponential

Alcohol differs from most substances in that it is eliminated at an approximately constant rate rather than a constant fraction. Once the metabolising enzymes are saturated, which happens at very low blood concentrations, clearance follows zero-order kinetics: roughly one standard drink per hour in an average adult, regardless of how much has been consumed.

This has a consequence people frequently get wrong. Doubling the amount drunk more than doubles the time to sober, because the body cannot speed up. Nothing accelerates it, and the popular remedies do not touch the rate: coffee counteracts drowsiness without changing blood alcohol, cold showers do nothing, and eating slows absorption if done beforehand but does not increase elimination afterwards.

• Only time lowers blood alcohol concentration. Coffee, showers, exercise and food do not.
• Food eaten before or during drinking slows absorption and lowers the peak, which is a real effect, but it does not change how long clearance takes.

Drinking level definitions

The categories below are the NIAAA definitions used in US research and public health guidance. They exist to make risk comparable across studies rather than to mark a safe amount, and current guidance from several bodies notes that less is better and that no level is entirely without risk.

حدود الاستخدام

• Standard drink definitions differ by country. A US standard drink is 14 grams of alcohol, a UK unit is 8 grams, and other countries range from roughly 8 to 20 grams, so the same drink converts differently.
• The one-drink-per-hour elimination figure is an average. Actual rate varies with sex, body composition, liver function, genetics and regular intake.
• The calculator estimates alcohol consumed, not blood alcohol concentration, which additionally depends on body water, sex, stomach contents and time course.
• Nothing here should be used to judge fitness to drive. Legal limits are defined on measured blood or breath concentration, and impairment begins below every legal limit.
• Alcohol interacts dangerously with many medications, and the categories above assume no such interaction.
• These definitions are for healthy non-pregnant adults. No amount is considered safe in pregnancy.

الأسئلة الشائعة

What counts as one standard drink?

In the US, any drink containing about 14 grams of pure alcohol: a 12 oz regular beer at 5 percent, a 5 oz glass of table wine at 12 percent, or 1.5 oz of 80-proof spirits. The UK unit is smaller at 8 grams.

How long does it take to sober up?

Roughly one standard drink per hour, because alcohol is eliminated at an approximately constant rate rather than a constant fraction. Doubling the amount consumed more than doubles the time, and nothing speeds the process up.

Does coffee help you sober up?

No. Caffeine counteracts drowsiness without changing blood alcohol concentration, which can make someone feel more capable while remaining equally impaired. Only time lowers blood alcohol.

Why does a pint of craft beer count as more than one drink?

Because a standard drink is a quantity of alcohol, not a serving size. A 16 oz pint at 7 percent ABV contains about 2.2 US standard drinks, compared with one for a 12 oz beer at 5 percent.

How much drinking counts as binge drinking?

The NIAAA defines it as 5 or more drinks for men, or 4 or more for women, within about two hours, which is the pattern that typically brings blood alcohol to 0.08 percent.

المراجع

1. National Institute on Alcohol Abuse and Alcoholism. What Is A Standard Drink?
2. National Institute on Alcohol Abuse and Alcoholism. Drinking Levels and Patterns Defined.
3. Roberts DM et al. Physiology, Zero- and First-Order Kinetics. StatPearls, NCBI Bookshelf.
4. MedlinePlus. Alcohol.