How Long Does Alcohol Actually Stay in Your System? Standard Drinks, Sleep and the Morning After

You had four drinks at dinner, slept a solid eight hours, and feel completely normal the next morning. So, how long does alcohol stay in your system, and are you clear to drive to work?

For most people, it takes far longer than they expect. Your body clears alcohol at a fixed, unhurried pace, and no amount of sleep, coffee or cold water speeds it up. That gap between feeling fine and being under the legal limit is where many otherwise careful drivers come unstuck.

Key Insights

• Your body clears roughly one standard drink per hour, and only time lowers your blood alcohol concentration (BAC).

• A standard drink is 10 grams of alcohol, which is often far smaller than what you're really poured.

• In Victoria, the limit is under 0.05 for full licence holders and 0.00 for learner, probationary and professional drivers.

• Sleep, coffee, a big breakfast and cold showers do nothing to sober you up faster.

• After a heavy night, you can still be over the limit well into the next morning or even the afternoon.

How Long Does Alcohol Stay in Your System?

Your liver does almost all the work, breaking down about 91% of the alcohol you drink, with small amounts leaving through your breath, sweat and urine. The catch is that the liver works at a steady rate, and it can't be rushed. The liver can only process around one standard drink an hour, which is why sobering up takes time.

As your liver works through the alcohol, your BAC drops slowly. VicRoads puts the fall at roughly 0.01 per hour, though it varies from person to person. The only thing that lowers your reading is time. Coffee, a cold shower, food, water and fresh air won't touch your BAC. They might make you feel more awake, which is arguably more dangerous, because feeling alert and being sober are two very different things.

What Counts as a Standard Drink?

An Australian standard drink is exactly 10 grams of pure alcohol, whether it's beer, wine or spirits.

The problem is that almost nothing you're served equals a neat single standard drink. An average glass of wine poured in a pub can be around 1.5 standard drinks, and a restaurant pour of red is often closer to 1.8. A schooner of full-strength beer and a generous home pour are both well over one. So the "three drinks" you think you had could easily be five or six standard drinks.

By law, every bottle, can, and cask in Australia lists its standard drinks on the label, and checking it is the simplest way to keep an honest count.

How Many Standard Drinks Can You Have and Still Drive?

There's no magic number that guarantees you'll stay under 0.05. Age, body size, sex, how much you've eaten, your fitness and even the health of your liver all change how fast alcohol hits your bloodstream and how quickly it clears.

As a very rough guide, drinking less than one standard drink per hour will keep most people under 0.05, because that's close to the average rate the body clears alcohol. But "most people" isn't "you", and it isn't a promise.

For a large group of drivers, the answer to how many standard drinks to drive on is simply zero. Under Victorian law, learner, probationary and professional drivers must have a BAC of 0.00, so a single drink is one too many.

Can You Sleep It Off? The Morning-After Problem

Sleep feels like it should reset the clock, but it doesn't. When people ask how long does alcohol stay in your system after a big night, they're usually hoping sleep counts for something. It doesn't. Your liver processes alcohol at the same rate whether you're awake or asleep, so a night's rest changes nothing about your BAC beyond the hours that have passed. You simply wake up further along the same slow curve.

Someone who drinks heavily into the early hours might hit a BAC of around 0.16 by midnight. Falling at roughly 0.01 an hour, they're still sitting near 0.05 at 11am the next day and don't return to 0.00 until late afternoon. That's about 17 hours from their last drink.

Morning-after driving is one of the most common ways people who never intended to drink drive end up losing their licence.

How Long After Drinking Can I Drive?

The frustrating part is that there's NO formula precise enough to trust with your licence. The one standard drink per hour figure is an average, not a guarantee, and it says nothing about the huge personal variation between drinkers.

So the practical answer to how long after drinking can you drive is this: we don’t know. Leave a generous margin, and when there's any doubt, don't drive. So plan the trip home before the first drink rather than after the last. Pre-organising a rideshare, taxi, public transport or a lift from someone sober costs a fraction of a lost licence and a behaviour change program.

If you've had a big night, treat the entire next day as suspect rather than assuming a coffee and a shower have done the job.

What Drink Driving Really Costs You in Victoria

The stakes are high, and not only legally. Alcohol impairs judgement, reaction time and the ability to judge distances. The Transport Accident Commission notes that at 0.08 BAC a driver is around five times more likely to be involved in a crash.

The legal consequences are steep too. In Victoria, every driver caught drink or drug driving must complete a Vicroads behaviour change program before they can apply for their licence back. On top of that, you can face a licence disqualification, a fine, a zero BAC condition for at least three years and an alcohol interlock fitted to your car. 

If you've already lost your licence, the road back runs through an accredited program, and that's where we come in. Drink Drive Victoria delivers VicRoads-approved programs across Melbourne and regional Victoria, including the first-time drink driving course and drug driving course, as well as the intensive behaviour change program for repeat offences and higher-range readings.

Our accredited drug and alcohol professionals have helped thousands of Victorians through this process without judgment. If a drink or drug driving offence has already cost you your licence, visit Drink Drive Victoria to book the program that gets you back on the road.