A glass of wine with dinner, then a short drive back to the hotel. At home that's well inside the limit. In the country you're visiting, it may have just put you over it — with a fine, a lost rental car or worse on the line.
The trouble is that "one drink is fine" is a habit, not a fact. What's legal at home may be illegal where you're driving, and the penalties for a foreign driver getting it wrong can be especially harsh. The limit isn't intuitive and your body has no warning light, which is exactly why the number matters more than how you feel.
Why the limit is so different everywhere
Blood alcohol limits run from fairly permissive to absolute zero, with no universal standard. Some countries set a moderate threshold, many set a stricter one, and a significant number enforce zero tolerance — any detectable alcohol at all is an offence. A few apply tougher limits to younger or newer drivers. So the same dinner-and-a-drink can be perfectly legal on one side of a border and a serious crime on the other.
How alcohol affects you also depends on your weight, sex, what and when you've eaten, and how fast you drank — which is why no simple "you can have X drinks" rule is ever truly safe. In a country with a low or zero limit, the genuinely safe number is almost always none.
The cost of getting it wrong
For a visiting driver, a drink-driving charge is rarely just a fine. It can mean your hire car taken away on the spot, leaving you stranded; your travel insurance refusing any related claim, since driving over the limit usually voids cover; and in stricter countries, detention or a driving ban. An accident while over the limit turns an expensive mistake into a potentially life-changing one. Against all that, the cost of not driving after a drink is trivial.
Get a rough sense of where you stand
This gives a very rough estimate only — it can't account for everything, and feeling fine is never proof you're under. Estimate yours below.
BAC estimator → rough guide, not proof
A rough estimate only. If you're driving, the safest choice is not to drink at all.
The simple, safe approach
Seasoned travellers solve this not with maths but with a habit: if they're driving, they don't drink, and if they're drinking, they don't drive. A taxi or rideshare back to the hotel costs a fraction of a fine and nothing next to the alternative. Check the local limit before you travel so you know what you're dealing with, never rely on how sober you feel, and remember alcohol can still be in your system the morning after — "I slept it off" has caught out many a driver at a morning checkpoint.
Go deeper
Questions
Is the drink-driving limit the same everywhere?
No — limits vary widely between countries, from moderate thresholds to strict ones to outright zero tolerance. Never assume your home limit applies abroad; check the local rule for wherever you'll be driving.
How many drinks can I safely have before driving?
There's no reliably safe number — it depends on your weight, sex, food, timing and the local limit. In countries with low or zero limits, the only genuinely safe amount is none. If you're driving, the simplest rule is not to drink at all.
What is zero tolerance?
It means any detectable alcohol in your system while driving is an offence — even a single drink can put you over. A number of countries apply this, and some apply it specifically to young or newly licensed drivers. Where it applies, don't drink and drive at all.
Could drink-driving void my travel insurance?
Almost certainly. Most travel and car-hire insurance excludes incidents where the driver was over the legal limit, so a related claim — medical, damage or liability — is likely to be refused, leaving you to pay potentially enormous costs yourself.
Can I still be over the limit the next morning?
Yes. Alcohol leaves the body slowly, so after a heavy night you can still be over the limit hours later, even when you feel fine. Morning checkpoints catch many drivers this way — if you drank a lot, don't assume you're safe to drive the next day.
What happens if I'm caught as a foreign driver?
Consequences vary by country but can include heavy fines, loss of the hire car, a driving ban, and in stricter places, detention. Penalties for visitors are not lighter — if anything they can be more disruptive. The safest course is simply never to drive after drinking abroad.
Blood alcohol limits and penalties vary by country and change over time, and the estimator is approximate only. This is general guidance, not legal or medical advice — never rely on it to decide whether to drive. If you're driving, the safest choice is not to drink at all.