How Long Does Alcohol Stay in Your System?

A roughly fixed clearance rate

The liver breaks down alcohol at a steady pace it can't be rushed. As a rule of thumb it clears about one standard drink per hour — a 12 fl oz beer, a 5 fl oz glass of wine or a 1.5 fl oz shot of spirits each count as one. Drink faster than that and alcohol builds up in your blood.

How long tests detect it

Detection windows differ by test: breath and blood roughly track current level (hours); urine can show alcohol or its markers for up to about 12-24 hours (longer with specialized tests); saliva a day or so; hair for up to about 90 days. "Feeling sober" does not mean your level is zero.

Never drink and drive

Because clearance is slow, you can be over the limit hours after your last drink — even the morning after a heavy night. Legal limits differ by country and are lower or zero for young or professional drivers. The only safe amount before driving is none; if in doubt, wait or find another way home.

Frequently asked questions

Can coffee or a cold shower sober me up?

No. They may make you feel more alert but do not lower your blood alcohol. Only your liver, over time, removes alcohol — nothing speeds that up.

Why does the same drink affect people differently?

Body weight, sex, body composition, food in the stomach and genetics all change how fast alcohol enters and how high blood alcohol climbs from the same amount.

How long until I'm safe to drive?

Plan on at least one hour per standard drink, and more if you drank heavily — often into the next morning. When unsure, don't drive; the estimate is not a legal guarantee.

Does eating before drinking help?

Food slows absorption, so your peak blood alcohol is lower and comes later — but it does not reduce the total you must clear or speed up elimination.