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Thailand

Blood Alcohol Content Calculator – Thailand Drink Driving Limit 🇹🇭

Driving in Thailand? The legal limit is 0.05% (50mg per 100ml) for most drivers, and just 0.02% (20mg%) for under-20s and new licence holders. Our BAC calculator estimates your blood alcohol content and when you'll be sober again.

50 mg/100 ml Drink-drive limit

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Alcohol Limit Thailand: 0.05% (50mg%) — 0.02% for New Drivers — 50 mg/100 ml

Most Thai drivers must stay under 0.05% (50mg of alcohol per 100ml of blood). A stricter 0.02% (20mg%) limit applies to drivers under 20, provisional or under-5-year licence holders, and unlicensed or suspended drivers. Exceeding the limit carries up to 1 year in jail, a ฿5,000–฿20,000 fine, and a licence suspension of at least 6 months. Refusing the test is treated as an admission of guilt.

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 }}

{{ drinkSummary(drink) }}

%

≈ {{ servingHint(drink) }}

Maximum number of drinks reached.

The results will show up here...
📈 Results
Current BACPeak BAC {{ initialSobriety }}{{ unitSign }} Drink-drive limit {{ countryLimit }}{{ unitSign }}
Safe Caution Impaired Intoxicated Dangerous
Above the Thai limit. Close to the 0.05% Thai limit — this estimate could already be over. Below the 0.05% Thai limit.
Time until {{ impactLimitLabel }}: {{ legalLimitTimeLabel }}
Time until {{ zeroTargetLabel }}: {{ sobrietyDuration }}

Alcohol Limit Thailand: 0.05% (50mg%) — 0.02% for New Drivers

General drivers (licence over 5 yrs) 50 mg%
Under 20 / new & provisional licence 20 mg%

Thailand Drink Driving Penalties & Alcohol Limit

Offence type No offence Below the legal limit – driving is permitted.
Offence type Over the 0.0 limit Zero-tolerance country — driving with any detectable alcohol is prohibited.
Offence type Over the legal limit You are over the legal limit and committing a drink-driving offence. Exact penalties depend on your BAC and local law.
Offence type Drink driving (criminal offence) Over the limit (50 / 20 mg%) Criminal offence — jail up to 1 year, a fine, and licence suspension; refusing the test counts as an admission.
Typical penalties
  • Up to 1 year jail
  • ฿5,000–฿20,000 fine
  • Licence suspension from 6 months
Offence type Causing an accident / repeat offence Causing injury or death Criminal offence — may result in a criminal record.
Typical penalties
  • 1–10 years jail
  • Up to ฿200,000 fine
  • Licence revoked
These are general penalties. Actual consequences may vary by local law and circumstances. Learn more →

Drink-drive limit

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Based on Thai law (0.05% / 50mg%) ·

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 0.05% Thai limit
For your own safety, we recommend using a rate no higher than the average.
Current BACPeak BAC {{ initialSobriety }}{{ unitSign }} Drink-drive limit {{ countryLimit }}{{ unitSign }}
Safe Caution Impaired Intoxicated Dangerous
Above the Thai limit. Close to the 0.05% Thai limit — this estimate could already be over. Below the 0.05% Thai limit.
Time until {{ impactLimitLabel }}: {{ legalLimitTimeLabel }}
Time until {{ zeroTargetLabel }}: {{ sobrietyDuration }}

Alcohol Limit Thailand: 0.05% (50mg%) — 0.02% for New Drivers

General drivers (licence over 5 yrs) 50 mg%
Under 20 / new & provisional licence 20 mg%

Thailand Drink Driving Penalties & Alcohol Limit

Offence type No offence Below the legal limit – driving is permitted.
Offence type Over the 0.0 limit Zero-tolerance country — driving with any detectable alcohol is prohibited.
Offence type Over the legal limit You are over the legal limit and committing a drink-driving offence. Exact penalties depend on your BAC and local law.
Offence type Drink driving (criminal offence) Over the limit (50 / 20 mg%) Criminal offence — jail up to 1 year, a fine, and licence suspension; refusing the test counts as an admission.
Typical penalties
  • Up to 1 year jail
  • ฿5,000–฿20,000 fine
  • Licence suspension from 6 months
Offence type Causing an accident / repeat offence Causing injury or death Criminal offence — may result in a criminal record.
Typical penalties
  • 1–10 years jail
  • Up to ฿200,000 fine
  • Licence revoked
These are general penalties. Actual consequences may vary by local law and circumstances. Learn more →
{{ afterLabel }} {{ $t('unit.' + units) }} Status
{{ result.time }} {{ result.drunkenness }}
  • Below the 0.05% Thai limit.
  • Close to the 0.05% Thai limit — this estimate could already be over.
  • Above the Thai limit.

This is general information, not legal advice, and the estimate is approximate. The only safe level before driving is zero.

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Sobriety Over Time

Your estimated BAC as your body clears the alcohol

Time until {{ zeroTargetLabel }} {{ sobrietyDuration }}
  • {{ lookaheadBacDisplay }}{{ unitSign }} Above the Thai limit. Close to the 0.05% Thai limit — this estimate could already be over. Below the 0.05% Thai limit.
  • {{ $t('unit.' + units) }}
  • Drink-drive limit ({{ countryLimit }}{{ unitSign }})
👮 Health impact and legal consequences
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{{ $t('impact.limit_note', { limit: impactLimitLabel }) }}

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Peak BAC: {{ peakBAC }}

💡 Advice: drink water, eat, and avoid driving. The Thai limit is 0.05% (0.02% for new drivers). 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 is the estimated alcohol in your blood, shown in mg% (mg per 100 ml), promille (‰) or as a percentage. Thai law is written in mg%, so 50 mg% is the same as 0.05%.

Legal limit

Most drivers must stay under 0.05% (50 mg%), but a stricter 0.02% (20 mg%) applies to drivers under 20, provisional or under-five-year licence holders, and unlicensed or suspended drivers. Going over carries up to 1 year in jail, a ฿5,000–฿20,000 fine and at least a 6-month licence suspension — and refusing the test is treated as an admission of guilt. Tourists on a foreign licence face exactly the same penalties.

Elimination rate

Your body removes alcohol at a roughly fixed 0.15 ‰ (about 0.015%) an hour, and nothing shortens it — a coffee, a cold shower or a plate of food change how you feel, not the reading. After a late night out on Khao San or Bangla Road you can still be over the limit at breakfast.

Standard Drinks

A standard drink is about 10 grams of pure alcohol — a 330 ml beer at 5%, a 100 ml glass of wine at 12%, or a 30 ml shot at 40%. Beware buckets and free-pour cocktails: they often hold three or more standard drinks.

Pure Alcohol

The total pure alcohol (ethanol) your body has absorbed, in grams — the basis for both your standard-drink count and your BAC.

Time vs. Sobriety Table

The table projects your BAC each hour, and with your first-drink time it maps them onto the time of day — useful the morning after, showing when you drop back under 50 mg%. Status icons mark which hours are safe to drive.

Sobriety Over Time Graph

A line chart of your BAC falling over the hours ahead, showing when it drops back under the 0.05% Thai limit and then to zero.

How Alcohol Affects You

A reference table matching BAC ranges to their typical effects on judgement, coordination and reaction time — impairment that begins well below the limit.

Legal limit reached in / Sober in / Peak BAC

Quick summary estimates:

  • Legal limit reached in: time until your BAC drops back under the 50 mg% (0.05%) Thai limit.

  • Sober in: time until it returns to ~0.

  • Peak BAC: the highest level reached in the session.

Thailand 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 Thailand drink?

Alcohol consumption per adult, per year

7.6L

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

Per adult, that is roughly:

461 beers ≈ 9/week
422 glasses of wine ≈ 8/week
475 shots ≈ 9/week
7.6 L
0.0 L Ø 3.1 7.6 L

142% above the regional average

Ranks #1 of 10 in South-East Asia Ranks #56 of 188 in the World Average in South-East Asia: 3.1 L

How neighbours compare

#1 Laos 11.2L #1 Western Pacific
#2 Vietnam 10.7L #3 Western Pacific
#3 Thailand 7.6L #1 South-East Asia
#4 Cambodia 5.4L #9 Western Pacific
#5 Myanmar 1.9L #7 South-East Asia
#6 Malaysia 0.8L #20 Western Pacific

How safe are the roads in Thailand?

Road traffic deaths per 100,000 people, per year

25.4 /100k

road traffic deaths per 100,000 people, 2021

~33% of road deaths linked to alcohol WHO estimate, 2019 · 22–47%
350 road deaths per week WHO estimate, 2021
117 alcohol-linked deaths per week WHO-derived estimate
25.4
1.3 Ø 15.9 28.2

60% more road deaths than the regional average

#8 safest of 9 in South-East Asia #180 safest of 195 worldwide Average in South-East Asia: 15.9 per 100k

How neighbours compare

#1 Malaysia 13.9 #19 Western Pacific
#2 Laos 16.4 #22 Western Pacific
#3 Vietnam 17.7 #25 Western Pacific
#4 Cambodia 18.8 #27 Western Pacific
#5 Myanmar 19.3 #7 South-East Asia
#6 Thailand 25.4 #8 South-East Asia

Latest available year shown per country.

LIMITS NEARBY

BAC limits in neighboring countries

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

MY

Malaysia

50mg/100 ml
Moderate
LA

Laos

50mg/100 ml
Moderate
KH

Cambodia

50mg/100 ml
Moderate
MM

Myanmar

80mg/100 ml
Relaxed
VN

Vietnam

0mg/100 ml
Zero tolerance

Alcohol Limit Thailand: 0.05% (50mg%) — 0.02% for New Drivers

Legal drink driving limits for Thailand

General drivers (licence over 5 yrs)
50mg%
Moderate
Under 20 / new & provisional licence
20mg%
Strict
Most Thai drivers must stay under 0.05% (50mg of alcohol per 100ml of blood). A stricter 0.02% (20mg%) limit applies to drivers under 20, provisional or under-5-year licence holders, and unlicensed or suspended drivers. Exceeding the limit carries up to 1 year in jail, a ฿5,000–฿20,000 fine, and a licence suspension of at least 6 months. Refusing the test is treated as an admission of guilt.
Verified with official source
Legal limits checked against ratchakitcha.soc.go.th
Last verified: 2026-09-04
Open the register

Thailand Drink Driving Penalties & Alcohol Limit

Consequences of drink driving in Thailand by severity

Over the limit (50 / 20 mg%)
Drink driving (criminal offence)
  • Up to 1 year jail
  • ฿5,000–฿20,000 fine
  • Licence suspension from 6 months
Causing injury or death
Causing an accident / repeat offence
  • 1–10 years jail
  • Up to ฿200,000 fine
  • Licence revoked

Source: Thailand Land Traffic Act (พระราชบัญญัติจราจรทางบก); Royal Thai Police.

Responsible Drinking & the 0.05% Limit in Thailand

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
The Thai limit is 0.05% (just 0.02% for new drivers). Use Grab, a taxi, or a tuk-tuk, or stay overnight.

Source: WHO; Thailand Land Traffic Act; Royal Thai Police.

How we calculate your BAC

The exact formula, step by step

Your result is not a guess. It comes from the Widmark equation, the same formula forensic toxicologists use in court. Here it is, worked through with an example.

BAC = A ÷ (r × W) − (β × t)

where A = grams of pure alcohol, r = body-water factor (0.68 for men, 0.55 for women), W = weight in kg, β = elimination rate (~0.15 g/L per hour), and t = hours since your first drink.

  1. Pure alcohol (A). Three 500 ml beers at 5% ABV hold 3 × 500 × 0.05 × 0.789 ≈ 59 g of pure alcohol.
  2. Body water (r × W). For an 80 kg man: 0.68 × 80 = 54.4.
  3. Peak level. A ÷ (r × W) = 59 ÷ 54.4 ≈ 1.09 g/L — the same as 1.09‰ or about 0.11% BAC.
  4. Subtract elimination. After 2 hours: 1.09 − (0.15 × 2) = 0.79 g/L.

The calculator runs this same equation on your own weight, sex, drinks and timing — the numbers above are only a worked example. Method based on E. M. P. Widmark (1932); results are an estimate, not a legal measurement.

What people actually log

SmartBAC has run over 17,000 calculations in recent weeks. Of every drink people log, beer is the most common by far — about 6 in 10 — ahead of spirits and then wine.

Anonymous, aggregated first-party usage data from SmartBAC, July–August 2026.

FAQ

How long does alcohol stay in your blood?

Your body removes alcohol at a fairly steady rate — roughly 0.15 ‰ per hour, or about one standard drink per hour. Starting from a BAC of 1.0 ‰, it would take about 7–10 hours to clear completely; from 1.5 ‰, more like 12 hours. From a single beer at around 0.3 ‰, it takes roughly 2–3 hours to reach zero.

That figure is an estimate, not a guarantee. The actual time depends on your weight, sex, metabolism, whether you have eaten, and your general health, so two people who reach the same BAC can sober up at different speeds. Detection windows differ from "safe to drive" windows — alcohol can be detected in breath or blood for hours and in urine for longer — but the figure that matters for driving in Thailand is whether your blood concentration is back under the legal limit, and ideally at zero.

How can I sober up faster?

The honest answer is that you cannot sober up faster. Your liver breaks down alcohol at an essentially fixed rate, and only time lowers your blood alcohol content. Popular "remedies" — black coffee, a cold shower, fresh air, exercise, a big meal after drinking, or being sick — do not change how quickly alcohol leaves your system.

What some of these can do is make you feel more alert, and that is precisely the danger: feeling more awake while your BAC is still above the limit can fool you into thinking you are fit to drive when you are not. Coffee, for example, masks tiredness without touching your alcohol level. Drinking water is sensible for rehydration and may ease a hangover, but it does not speed up sobering up. The only safe plan is to wait until your BAC is genuinely back down — or simply not drive that day.

How accurate are Thai police breathalysers?

Thai police use officially approved and regularly calibrated breathalysers, which gives their readings legal weight in court. The devices carry a small built-in margin of error — typically a few percent on the displayed reading — and that tolerance is already factored into how they are certified for evidential use. Alcohol lingering in the mouth (from mouthwash, cough syrup, or a recent sip) can briefly raise readings, so officers normally allow a short wait before testing, and you can request a confirmatory blood test if you dispute the result.

Consumer-grade personal breathalysers are noticeably less accurate than police equipment, lose calibration over time, and have no legal standing in Thailand. They can be useful for awareness — particularly the morning after — but should never be your green light to drive. Online calculators don't measure anything; they model your BAC from the inputs you provide, so if your details are off, the estimate is off too.

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