How many drinks puts me over the limit?

Approximate, varies by body weight, sex, food intake, and drink size. For a 70 kg adult: 2 standard drinks bring most US-Canada drivers to 0.05–0.08 %. In Japan or Korea, half a 350 ml beer can exceed 0.03 %. The only safe answer for travel: do not drink and drive at all.

Is the limit different for commercial drivers?

Yes in every country. US: 0.04 % for CDL (commercial driver licence) holders. Canada: 0.04 % in most provinces for commercial. Japan and Korea apply the same threshold but with harsher penalties for commercial drivers.

Federally illegal in the US (Schedule I) and Japan and Korea. Canada legalised recreational cannabis in 2018 with a per-se criminal driving limit of 2 ng/mL THC. Driving with any detectable cannabis is illegal in Japan and Korea regardless of medical legality elsewhere.

Will breath-test refusal protect me?

No — refusal is itself a criminal offence in all four countries and typically carries penalties equal to or greater than the underlying impaired-driving charge.

BAC (drink-driving) limits around the world — and why "one beer" varies so much

A driver legally sober in the United States may be criminally impaired in Japan. The legal BAC threshold for driving differs by more than 2× across the four countries we cover: 0.08% in the US and Canada, 0.03% in Japan and Korea. For a 70 kg adult, the practical implication is roughly "two beers" in North America versus "half a beer" in East Asia.

Beyond the headline number, the legal architecture differs sharply. Some jurisdictions distinguish administrative (licence suspension) and criminal (court) tiers; others treat any over-limit driving as a single criminal offence. Zero-tolerance laws for young or commercial drivers are nearly universal but defined differently. We compare the headline thresholds, enforcement style, and tier structure below.

⚠️ Not legal advice. Traffic and insurance laws change. Verify with the official source before you drive. Full disclaimer.

Side-by-side comparison

Country	Adult BAC limit	Notes
🇺🇸United States	0.08 % (Utah: 0.05 %)	Federal standard 0.08 % since 2004. Utah dropped to 0.05 % in 2018. Most states: zero tolerance (0.00–0.02 %) for drivers under 21 and commercial drivers (CDL: 0.04 %). (NHTSA — Drunk Driving)
🇯🇵Japan	0.03 % (criminal at 0.05 %)	Administrative offence at 0.03 %; criminal "drunk driving" at 0.05 % and higher. "Vehicle provision" (giving keys to a drunk person) and "passenger" (riding with a drunk driver who you knew was drinking) are also criminalised. (Japan NPA)
🇰🇷South Korea	0.03 % (criminal at 0.08 %)	Threshold lowered from 0.05 % to 0.03 % in 2019 (Yoon Chang-ho Law). Repeat offence: licence revocation + prison. (KoROAD)
🇨🇦Canada	0.08 % federal (provincial warn at 0.05 %)	Criminal Code: 0.08 %. Provinces add administrative suspensions starting at 0.05 % (BC, Ontario, Alberta). Cannabis: 2 ng/mL THC criminal limit. (Transport Canada)

Country detail

United States

The 0.08 % federal standard was tied to highway-funding incentives starting in 2000 and effectively forced every state to adopt it. Utah went to 0.05 % in 2018 — NHTSA evaluation showed crash reductions. Zero-tolerance laws for under-21 drivers are universal. Penalties scale from administrative licence suspension at first offence to felony charges at multiple offences. Ignition-interlock devices are mandated in most states after a first conviction.

Japan

Japan's 0.03 % threshold is one of the strictest in the OECD, paired with criminal "drunk driving" at 0.05 %+. Most distinctive: Japanese law criminalises "vehicle provision" (knowingly giving keys to a drunk person) and "drunk-passenger" (riding with a drunk driver knowingly). Enforcement is heavy; breath-checks at random sobriety stops are common, especially around bar districts after midnight. The cultural norm is "if you drink, you don't drive at all".

South Korea

Korea lowered the threshold from 0.05 % to 0.03 % in June 2019 after the death of a soldier named Yoon Chang-ho in a drink-driving collision (the "Yoon Chang-ho Law"). Criminal threshold begins at 0.08 %. Repeat offenders face licence revocation and imprisonment. Like Japan, Korean enforcement uses frequent breath-checks; foreign drivers are not exempt.

Canada

Canada's Criminal Code BAC limit is 0.08 % (same as US), but provinces layer administrative penalties on top — BC, Ontario, and Alberta will suspend a licence at 0.05 % even without a criminal charge. Cannabis impairment is criminalised at 2 ng/mL THC in blood. Roadside testing devices for both alcohol and cannabis are authorised.

Frequently asked

How many drinks puts me over the limit?: Approximate, varies by body weight, sex, food intake, and drink size. For a 70 kg adult: 2 standard drinks bring most US-Canada drivers to 0.05–0.08 %. In Japan or Korea, half a 350 ml beer can exceed 0.03 %. The only safe answer for travel: do not drink and drive at all.
Is the limit different for commercial drivers?: Yes in every country. US: 0.04 % for CDL (commercial driver licence) holders. Canada: 0.04 % in most provinces for commercial. Japan and Korea apply the same threshold but with harsher penalties for commercial drivers.
What about cannabis?: Federally illegal in the US (Schedule I) and Japan and Korea. Canada legalised recreational cannabis in 2018 with a per-se criminal driving limit of 2 ng/mL THC. Driving with any detectable cannabis is illegal in Japan and Korea regardless of medical legality elsewhere.
Will breath-test refusal protect me?: No — refusal is itself a criminal offence in all four countries and typically carries penalties equal to or greater than the underlying impaired-driving charge.

Sources

[1]NHTSA — Drunk Driving — NHTSA · accessed 2026-04-23
[2]NHTSA — Utah's .05% Law Shows Promise — NHTSA · accessed 2026-04-23
[3]National Police Agency — Rules of the Road — Japan NPA · accessed 2026-04-23
[4]KoROAD — Road Traffic Authority — KoROAD · accessed 2026-04-23
[5]Transport Canada — Transport Canada · accessed 2026-04-23