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Drink Driving Limit Calculator

The legal limit where you are, an estimate of where this arithmetic puts you, and how long alcohol actually takes to leave. It is not permission to drive.

Your estimated BAC
0.055
Under the limit on this estimate — which is not permission The limit in United States is 0.080
Nought to 0.20 BAC, always — the axis never rescales
You · 0.055
Under the limit — not the same as unimpaired Inside the error of this arithmetic At or over the limit

Under the legal limit on this estimate, and impaired all the same: reaction time and divided attention are measurably worse from about 0.02, and the limit is a line in law rather than a line where impairment starts. Never use this tool to decide whether to drive.

Back under the limit in 0h 0m On this estimate you are already under it, which is not the same as being safe or legal to drive.
Back to nought in 3h 41m At the average elimination rate this tool assumes, about 0.015% BAC an hour. Coffee, food, a shower and a run change none of it.
Which is roughly 2:26 AM On your device’s clock. Individual rates differ, so treat it as the earliest rather than the answer.

Your details

Four inputs, and the arithmetic behind them is the Widmark equation. It cannot see the other dozen things that move a real reading.

Weight
Rounded is fine. A stone either way moves the estimate by a few thousandths — which is smaller than the gap this page tells you not to trust.
Biological sex
This picks the Widmark r factor — 0.68 for men, 0.55 for women — because alcohol spreads through body water and the proportion of it differs.
Number of drinks 3 drinks
One standard drink is 12oz of beer, 5oz of wine or 1.5oz of spirits. A large glass of wine is nearer two, and a home pour is nearer three.
Time spent drinking 2 hours
From the first drink to the last, not the time since you stopped. Your liver has been clearing alcohol the whole way through.
Cleared.

What to do instead

All four are cheaper than the cheapest possible version of the alternative.

A rideshare The fare is the price of the evening, not an extra.
A taxi, called Works where the apps do not, and takes cash.
Wait it out The clock above is the only thing that lowers the number.
Stay where you are A sofa is a worse night’s sleep and a much better morning.

Drink driving limits by country

Headline national limits. Lower ones apply to novice, professional and commercial drivers in most of these places, and laws change — check the current rules where you are driving.

CountryBAC limitNotes
United States 0.08% Utah: 0.05%. Commercial: 0.04%. Under-21: 0.00%
United Kingdom 0.08% Scotland: 0.05%
Australia 0.05% Learner/P-plate: 0.00%
Canada 0.08% Warn range 0.05–0.08
Germany 0.05% Novice: 0.00%
France 0.05% Novice: 0.02%
Japan 0.03% —
Norway 0.02% —
Sweden 0.02% —
India 0.03% —
Brazil 0.00% Zero tolerance
Russia 0.03% —
New Zealand 0.05% Under-20: 0.00%
Ireland 0.05% Professional: 0.02%

Sobering up: myths vs. facts

Six things people believe, and what each one actually does to a blood alcohol reading.

Myth Coffee sobers you up.
What is true

Coffee may make you feel more alert, but it does not lower your BAC or reduce impairment. You’ll be a wide-awake drunk.

Myth A cold shower will sober you up.
What is true

Cold water may shock you awake temporarily, but your BAC stays exactly the same. Only time metabolizes alcohol.

Myth Eating food after drinking absorbs the alcohol.
What is true

Food before drinking slows absorption, but eating after won’t lower your BAC. The alcohol is already in your bloodstream.

Myth Throwing up gets rid of the alcohol.
What is true

Most alcohol is absorbed within 20 minutes. Vomiting only removes what’s still in your stomach, not what’s already in your blood.

Myth Exercise and sweating burns off alcohol.
What is true

Only about 5% of alcohol leaves through sweat and breath. Your liver does 95% of the work at a fixed rate of roughly 0.015% BAC per hour.

Myth Sleeping it off means you’re fine to drive in the morning.
What is true

If you drank heavily, you may still be over the legal limit the next morning. Many drink-driving arrests happen the morning after.

How this is calculated

Estimated BAC comes from the Widmark equation (body weight, biological sex, grams of pure alcohol consumed, hours elapsed, and an average elimination rate of about 0.015% BAC per hour). Legal limits in the reference table are the headline national limits and ignore lower limits that apply to novice, professional and commercial drivers, plus local variations. Laws change — always check the current rules for the country you are driving in.

Sources

Our editorial policy explains how these tools and articles are researched and kept up to date.

Why This Matters

Sobering Up Myths Debunked

The most dangerous thing about alcohol impairment is how normal you can feel while still being significantly over the legal limit. Your brain is the first organ affected, which means your ability to judge your own impairment is compromised from the very first drink.

There are no shortcuts. Coffee, cold showers, exercise, food, and fresh air will not lower your blood alcohol level. Only time works. Your liver metabolizes alcohol at a fixed rate of approximately 0.015% BAC per hour — roughly one standard drink per hour — and nothing can speed that up.

“Sleeping it off” is particularly deceptive. A heavy night of drinking can leave you over the legal limit well into the following morning. If you had 10 drinks ending at midnight, you could still be impaired at noon the next day. The morning after calculator draws that out hour by hour from the time you stopped — not as a verdict, since nothing can give you one, but so the size of the overhang is on the page rather than in your head.

Drink Driving Laws by Country

Legal BAC limits vary dramatically around the world. The United States and United Kingdom set the limit at 0.08%, one of the highest in the developed world. Most of Europe, Australia, and New Zealand use 0.05%, while Scandinavian countries enforce limits as low as 0.02%.

Several countries operate zero-tolerance policies. Brazil, Hungary, the Czech Republic, and many Middle Eastern nations set the legal limit at 0.00%. Many countries also enforce stricter limits for novice drivers, commercial drivers, and young drivers.

Penalties range from fines and license suspension to mandatory jail time. In some jurisdictions, a drink-driving conviction results in a permanent criminal record. Many countries impound your vehicle on the spot.

Regardless of your country’s legal limit, impairment begins well below any legal threshold. Studies show measurable impairment in reaction time and divided attention at BAC levels as low as 0.02%. The safest BAC for driving is always 0.00%.

Asked and answered

Frequently Asked Questions

What is the legal drink driving limit?
In most US states, the legal limit is 0.08% BAC. For commercial drivers it's 0.04%. In the UK, Scotland, and many other countries, the limit is 0.05%. Some countries have zero-tolerance policies.
How many drinks can I have and still drive?
There is no safe universal answer. BAC depends on your weight, sex, how fast you drank, and whether you ate. The safest answer is: if you've been drinking, don't drive.
How long should I wait after drinking to drive?
Your body eliminates alcohol at about 0.015% BAC per hour. As a rough guide, wait at least 1 hour per standard drink consumed, plus an extra hour for safety. But individual metabolism varies significantly.
Does coffee or food help me sober up faster?
No. Nothing speeds up alcohol metabolism — not coffee, not food, not cold showers, not exercise. Only time reduces your BAC. Coffee may make you feel more alert, but your BAC and impairment remain the same.

BAC Calculator

An estimate of blood alcohol from what you drank, your weight and the hours since. Never a driving test.

Alcohol Units Calculator

Any drink turned into UK units and US standard drinks, measured against the weekly guideline.

True Cost of Drinking

What a year of your current drinking costs in money, hours and calories, from the amount you actually drink.

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