Japan

Blood Alcohol Content Calculator – Japan Drink Driving Limit 🇯🇵

Driving in Japan? The legal threshold for 酒気帯び (alcohol-affected) driving is 0.15 mg of alcohol per litre of breath — about 0.03% blood alcohol. Our BAC calculator estimates your blood alcohol content and when you'll be under the limit again. Since November 2024, the same 0.15 mg/L limit also applies to cycling.

0.3 ‰ Drink-drive limit

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ℹ️ Information

CONTEXT
🌎 Country
Show results in
ABOUT YOU
Sex
⚖️ Weight

lbs

⏱️ Start time of drinking (optional) Time of your first drink (not required)

🕒

⏳ Or: hours ago —
0h6h12h18h24h

🍹🍸🍺 Drinks

Drink {{index+1}} 🍷

%

Maximum number of drinks reached.

The results will show up here...
📈 Results
Current BACPeak BAC {{ initialSobriety }}{{ unitSign }} Measured for Now · Drink-drive limit {{ countryLimit }}{{ unitSign }}
Status:
Above the Japanese limit – driving now is a criminal offence. Approaching the 0.15 mg/L Japanese limit – do not drive. Below the 0.15 mg/L Japanese limit — but the only fully safe option before driving is zero.
{{ legalLimitTimeLabel }}

Drink-drive limit

{{ countryLimit }}{{ unitSign }}
Based on Japanese law (0.15 mg/L breath ≈ 0.03%) ·

Elimination rate

{{ decayRateDisplay }}{{ unitSign }} / h
Typical average

Standard Drinks

{{ standardDrinks }}🍺
Approx. consumed

Pure Alcohol

{{ results.length > 0 ? results[0].pureAlcoholMl : '0' }} {{ qunits }}
Pure alcohol consumed

Pure Alcohol (g)

{{ alcoholGrams }} g
Total ethanol consumed

Calories

{{ calories }} kcal
From alcohol only — mixers add more

Time over limit

{{ timeOverLimit || '0m' }}
Estimated duration above the 0.15 mg/L Japanese limit
For your own safety, we recommend using a rate no higher than the average.
Current BACPeak BAC {{ initialSobriety }}{{ unitSign }} Measured for Now · Drink-drive limit {{ countryLimit }}{{ unitSign }}
Status:
Above the Japanese limit – driving now is a criminal offence. Approaching the 0.15 mg/L Japanese limit – do not drive. Below the 0.15 mg/L Japanese limit — but the only fully safe option before driving is zero.
{{ legalLimitTimeLabel }}
{{ afterLabel }} {{ $t('unit.' + units) }} Status
{{ result.time }} {{ result.drunkenness }}
  • Below the 0.15 mg/L Japanese limit — but the only fully safe option before driving is zero.
  • Approaching the 0.15 mg/L Japanese limit – do not drive.
  • Above the Japanese limit – driving now is a criminal offence.
Create a pop-up notification
📉 Sobriety Over Time
👮 Health impact and legal consequences
{{ item.title }}
{{ legalLimitTimeLabel }} Sober in: {{ sobrietyTime }} Peak BAC: {{ peakBAC }}

💡 Advice: drink water, eat, and avoid driving. Japan's threshold is just 0.15 mg/L of breath (≈0.03%). If you are anywhere near it, find another way home.

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Attention‼️ The results are only approximate, so make sure you are sober before driving.

About results
Current BAC

Your Current BAC shows your estimated blood alcohol concentration right now, displayed as mg/L of breath, promille (‰) or a percentage. This reflects how much alcohol is in your bloodstream and is used to assess impairment.

Legal limit

In Japan, 酒気帯び運転 (alcohol-affected driving) begins at 0.15 mg/L of breath (≈0.03% blood alcohol). 0.15–0.25 mg/L means 13 demerit points and a 90-day suspension; 0.25 mg/L or more means 25 points and revocation. If alcohol leaves you unable to drive normally, it becomes 酒酔い運転 (drunk driving) — 35 points, revocation, and up to 5 years in prison or a ¥1,000,000 fine.

Elimination rate

Your body metabolises alcohol at a steady rate — typically ~0.15 ‰ per hour. Nothing — not coffee, not a cold shower, not exercise — speeds this up.

Standard Drinks

One standard unit ≈ 20g of pure alcohol — equivalent to a 500ml beer at 5%, 180ml of sake (1 gō), a 200ml glass of wine at 12%, or a 60ml double whisky at 40%.

Pure Alcohol

This is the total amount of pure alcohol (ethanol) your body has absorbed, in grams. Useful for comparing against guidance — Japan's MHLW suggests keeping to about 20g per day.

Time vs. Sobriety Table

The table lists how your BAC is expected to change with each hour passed — and when a Start time of drinking is provided, it aligns these estimates with the exact time of day you began drinking. Particularly useful for the morning-after check before driving the next day.

Sobriety Over Time Graph

A visual line chart plotting your estimated BAC decline over hours. It helps you see when your BAC drops back under the 0.15 mg/L Japanese limit and when it reaches zero.

How Alcohol Affects You

This reference table shows ranges of BAC and typical effects on your body and behaviour — from mild alertness changes to severe impairment.

Legal limit reached in / Sober in / Peak BAC

These summaries give quick key estimates:

  • Legal limit reached in: time until your BAC drops back under the 0.15 mg/L Japanese limit.

  • Sober in: total time until BAC reaches ~0.00.

  • Peak BAC: the highest BAC value recorded in the session.

Japan Drink Driving Limit & Alcohol Calculator Data

Five factors that determine your result

Weight
Body weight determines how alcohol distributes in the body — more weight means a lower blood alcohol concentration.
Sex
Men and women metabolise alcohol at different rates because of differences in body water content.
Amount
The amount of pure alcohol consumed is the main factor that determines your BAC result.
Strength
A higher strength (%) means more ethanol in the same drink serving.
Time
The time of your first drink shows how BAC changes hour by hour and when you'll be sober again.

How much does Japan drink?

Alcohol consumption per adult, per year

6.3L

litres of pure alcohol per adult (15+), per year

Per adult, that is roughly:

252 beers ≈ 5/week
350 glasses of wine ≈ 7/week
394 shots ≈ 8/week
6.3 L
0.1 L Ø 4.2 11.2 L

51% above the regional average

Ranks #7 of 25 in Western Pacific Ranks #71 of 188 in the World Average in Western Pacific: 4.2 L

How neighbours compare

#1 Russia 10.5L #22 Europe
#2 Japan 6.3L #7 Western Pacific
#3 China 4.5L #10 Western Pacific
#4 Singapore 2.0L #15 Western Pacific
LIMITS NEARBY

BAC limits in neighboring countries

Explore the legal blood alcohol concentration (BAC) limits for drivers in nearby countries.

KR

South Korea

0.3‰
Strict
CN

China

0.2‰
Strict
TW

Taiwan

0.5‰
Moderate
RU

Russia

0.3‰
Strict
SG

Singapore

0.8‰
Relaxed

Alcohol Limit Japan: 0.15mg/L Breath (酒気帯び) — Plus 酒酔い With No Number

Drink driving thresholds for Japan (酒気帯び / 酒酔い)

Alcohol-affected (breath 0.15–0.25 mg/L)
0.15mg/L
Moderate
Alcohol-affected 0.25 mg/L+ / drunk driving
0.25mg/L
Strict
Japan's drink-driving threshold is 0.15 mg/L of breath (about 0.03% blood alcohol). 0.15–0.25 mg/L means 13 demerit points and a 90-day suspension; 0.25 mg/L or more means 25 points and licence revocation (2-year disqualification). If alcohol leaves you unable to drive normally, it is treated as 酒酔い (drunk driving) regardless of the number — 35 points, revocation (3-year disqualification), and up to 5 years in prison or a ¥1,000,000 fine.

🚲 Bicycles count too: since the November 2024 law change, riding a bicycle while alcohol-affected is also punishable. Check that the alcohol has cleared with this calculator before you ride, not just before you drive.

Japan Drink Driving Penalties, Demerit Points & Fines

Consequences of drink driving in Japan by severity

Alcohol-affected (0.15 mg/L+)
  • 13–25 demerit points
  • 90-day suspension to revocation (2-yr disqualification)
  • Up to 3 years prison or ¥500,000 fine
Drunk driving / causing injury
  • 35 demerit points, licence revoked (3-yr disqualification)
  • Up to 5 years prison or ¥1,000,000 fine
  • Far longer where death or injury results

Source: Road Traffic Act (道路交通法); National Police Agency (警察庁). Penalties vary by case.

Responsible Drinking & Japan's 0.15mg/L Limit

Practical tips for safer drinking

Pace yourself
Stick to the "one drink per hour" rule – your liver needs time to process alcohol.
Eat before and while drinking
A solid meal slows alcohol absorption – an empty stomach raises BAC faster.
Drink water
After each alcoholic drink, have a glass of water – it reduces dehydration and health risks.
Don't drive
Japan's threshold is just 0.15 mg/L of breath. Use a taxi, a 代行 (daikō) service, or stay overnight.

Source: WHO; Japan Ministry of Health, Labour and Welfare (MHLW); Road Traffic Act.

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