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United Kingdom

When Can I Drive After Drinking? UK Alcohol Calculator 🇬🇧

Calculate your blood alcohol level and see if you are within the drink and drive limit in the UK. Our BAC calculator helps you estimate units and sobriety time.

80 mg/100 ml Drink-drive limit

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Drink Drive Limit in England, Scotland & Wales — 80 mg/100 ml

The 80 mg/100ml blood limit applies in England, Wales and Northern Ireland (35 µg/100ml breath). Scotland has enforced a lower 50 mg/100ml limit since December 2014 (22 µg/100ml breath). The UK has one of the highest limits in Europe — most drivers can be impaired well before they exceed it.

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 }}

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%

≈ {{ 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
Over the legal limit – driving is illegal. Approaching the legal limit – driving not advised. Likely under the limit, but drive with care.
{{ legalLimitTimeLabel }}
Sober in: {{ sobrietyTime }}

Drink Drive Limit in England, Scotland & Wales

All drivers (E&W, NI) 80 mg/100ml
Scotland (separate limit) 50 mg/100ml

Drink Driving Penalties & Alcohol Limit UK

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) 80–149 mg/100 ml Criminal offence from 80 mg/100 ml — conviction carries a mandatory minimum 12-month disqualification.
Typical penalties
  • Drink-driving offence — fine £1,000–£5,000+
  • Driving ban 12–36 months
  • Up to 6 months imprisonment
Offence type High-excess drink driving 150+ mg/100 ml Criminal offence — may result in a criminal record.
Typical penalties
  • Very high excess — fine £5,000+ (unlimited)
  • Ban 3+ years, possible lifetime
  • 6–12 months imprisonment, criminal record
These are general penalties. Actual consequences may vary by local law and circumstances. Learn more →

Drink-drive limit

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Based on UK law ·

Elimination rate

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Typical average

Standard Drinks

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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

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Estimated duration above the legal driving 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
Over the legal limit – driving is illegal. Approaching the legal limit – driving not advised. Likely under the limit, but drive with care.
{{ legalLimitTimeLabel }}
Sober in: {{ sobrietyTime }}

Drink Drive Limit in England, Scotland & Wales

All drivers (E&W, NI) 80 mg/100ml
Scotland (separate limit) 50 mg/100ml

Drink Driving Penalties & Alcohol Limit UK

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) 80–149 mg/100 ml Criminal offence from 80 mg/100 ml — conviction carries a mandatory minimum 12-month disqualification.
Typical penalties
  • Drink-driving offence — fine £1,000–£5,000+
  • Driving ban 12–36 months
  • Up to 6 months imprisonment
Offence type High-excess drink driving 150+ mg/100 ml Criminal offence — may result in a criminal record.
Typical penalties
  • Very high excess — fine £5,000+ (unlimited)
  • Ban 3+ years, possible lifetime
  • 6–12 months imprisonment, criminal record
These are general penalties. Actual consequences may vary by local law and circumstances. Learn more →
{{ afterLabel }} {{ $t('unit.' + units) }} Status
{{ result.time }} {{ result.drunkenness }}
  • Likely under the limit, but drive with care.
  • Approaching the legal limit – driving not advised.
  • Over the legal limit – driving is illegal.
Create a pop-up notification

Sobriety Over Time

Your estimated BAC as your body clears the alcohol

Sober in {{ sobrietyTime }}
  • {{ lookaheadBacDisplay }}{{ unitSign }} Over the legal limit – driving is illegal. Approaching the legal limit – driving not advised. Likely under the limit, but drive with care.
  • {{ $t('unit.' + units) }}
  • Drink-drive limit ({{ countryLimit }}{{ unitSign }})
👮 Health impact and legal consequences
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Peak BAC: {{ peakBAC }}

💡 Advice: drink water, eat, and avoid driving until you are under the legal limit and ideally fully sober.

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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 blood alcohol concentration in your bloodstream right now, shown as a percentage. UK police measure the same thing at the roadside in micrograms of alcohol per 100ml of breath (µg), then confirm it with an evidential breath, blood or urine test at the station — this figure is the blood-percentage equivalent so you can judge where you stand against the drink-drive limit.

Legal limit

The drink drive limit uk is 80mg of alcohol per 100ml of blood (0.08 % BAC) in England, Wales and Northern Ireland — 35µg/100ml of breath. Scotland has enforced a lower 50mg/100ml (0.05 % BAC, 22µg breath) limit since December 2014. That leaves England and Wales with one of the highest limits in Europe, yet most drivers are meaningfully impaired well before they reach it, which is why the safest amount before driving is none.

Elimination rate

This is the average rate your liver metabolises alcohol — roughly 0.015 % BAC per hour, or about one UK unit an hour, though it varies with body size and metabolism. Nothing speeds it up: coffee, a cold shower, water or food change how you feel but not how fast alcohol leaves your blood. This is why a heavy night can leave you over the limit the following morning — use the morning after calculator before you drive to work.

Standard Drinks

In the UK one unit is 10ml (8g) of pure alcohol. This total converts your drinks into units so you can weigh them against the NHS low-risk guideline of 14 units a week, spread over three or more days. For reference a pint of 5.2 % lager is about 3 units, a 175ml glass of 13 % wine roughly 2.3 units, and a single 25ml spirit measure 1 unit — so a couple of strong pints already carries you toward the limit.

Pure Alcohol

The grams of pure alcohol (ethanol) your body has absorbed so far — the raw figure the unit count and your BAC are both derived from.

Time vs. Sobriety Table

The table projects how your BAC changes hour by hour — and when you give a start time of drinking, it maps those estimates onto the actual time of day. Start at 8:00 pm and the column reads your projected BAC at 8:00 pm (Now), 9:00 pm (1h), 10:00 pm (2h) and on, so you can see the clock time your BAC is likely to drop back under the drink-drive limit. Status icons flag whether each hour is safe to drive, making it easier to plan a taxi home or a rest before the morning commute.

Sobriety Over Time Graph

A line chart of your estimated BAC declining over the hours ahead, so you can see at a glance when it falls below the legal and the genuinely safe levels.

How Alcohol Affects You

A reference table matching BAC ranges to their typical effects on your body and behaviour — from subtle changes in judgement and reaction time to serious impairment at higher levels.

Legal limit reached in / Sober in / Peak BAC

These summaries give the key estimates at a glance:

  • Legal limit reached in: the time until your BAC likely falls below the applicable drink-drive limit (80mg, or 50mg in Scotland).

  • Sober in: total time until your BAC returns to ~0.000 %.

  • Peak BAC: the highest BAC value reached during the session.

UK Drink Drive 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 United Kingdom drink?

Alcohol consumption per adult, per year

10.9L

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

Per adult, that is roughly:

384 beers ≈ 7/week
606 glasses of wine ≈ 12/week
681 shots ≈ 13/week
10.9 L
0.7 L Ø 8.9 17.1 L

23% above the regional average

Ranks #18 of 51 in Europe Ranks #23 of 188 in the World Average in Europe: 8.9 L

How neighbours compare

#1 France 11.2L #12 Europe
#2 United Kingdom 10.9L #18 Europe
#3 Scotland 10.9L #18 Europe
#4 Ireland 10.5L #22 Europe
#5 Netherlands 8.7L #30 Europe
#6 Belgium 8.7L #30 Europe

How safe are the roads in United Kingdom?

Road traffic deaths per 100,000 people, per year

2.4 /100k

road traffic deaths per 100,000 people, 2021

~40% of road deaths linked to alcohol WHO estimate, 2019 · 28–56%
31 road deaths per week WHO estimate, 2021
12 alcohol-linked deaths per week WHO-derived estimate
2.4
0.0 Ø 6.7 17.2

64% fewer road deaths than the regional average

#6 safest of 53 in Europe #9 safest of 195 worldwide Average in Europe: 6.7 per 100k

How neighbours compare

#1 United Kingdom 2.4 #6 Europe
#2 Scotland 2.4 #6 Europe
#3 Ireland 3.2 #10 Europe
#4 Netherlands 3.2 #11 Europe
#5 Belgium 4.0 #16 Europe
#6 France 4.6 #19 Europe

Latest available year shown per country.

LIMITS NEARBY

BAC limits in neighbouring countries

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

SCOT

Scotland

50mg/100 ml
Moderate
IE

Ireland

50mg/100 ml
Moderate
FR

France

50mg/100 ml
Moderate
NL

Netherlands

50mg/100 ml
Moderate
BE

Belgium

50mg/100 ml
Moderate

Drink Drive Limit in England, Scotland & Wales

Drink-drive limits in the UK (England, Wales & Northern Ireland)

All drivers (E&W, NI)
80mg/100ml
Relaxed
Scotland (separate limit)
50mg/100ml
Moderate
The 80 mg/100ml blood limit applies in England, Wales and Northern Ireland (35 µg/100ml breath). Scotland has enforced a lower 50 mg/100ml limit since December 2014 (22 µg/100ml breath). The UK has one of the highest limits in Europe — most drivers can be impaired well before they exceed it.

Drink Driving Penalties & Alcohol Limit UK

Consequences of exceeding the legal drink-drive limit

80–149 mg/100 ml
Drink driving (criminal offence)
  • Drink-driving offence — fine £1,000–£5,000+
  • Driving ban 12–36 months
  • Up to 6 months imprisonment
150+ mg/100 ml
High-excess drink driving
  • Very high excess — fine £5,000+ (unlimited)
  • Ban 3+ years, possible lifetime
  • 6–12 months imprisonment, criminal record

Source: UK Government, DVLA, and Alcohol Law Enforcement Policies

Tips for Responsible Drinking & Morning After Calculator

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
Even small amounts of alcohol impair reaction time. If in doubt, call a taxi or stay overnight.

Source: NHS, Drinkaware, and Public Health England

Official sources & references

The limits and penalties on this page come from official government sources

Confirm the current rules directly with the responsible authorities:

Laws change — always check the latest limits and penalties with the official source before driving.

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 it take for a BAC of 0.1% to leave the body?

Your body removes alcohol at a fairly steady rate — roughly 0.015% BAC per hour, or about one UK unit per hour — and nothing reliably speeds this up. Starting from a BAC of 0.1% (100mg/100ml of blood), it would therefore take in the region of 6 to 8 hours for the alcohol to clear completely.

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. It is also worth noting that 0.1% is well above the UK drink drive limit — 80mg/100ml in England, Wales, and Northern Ireland, and 50mg/100ml in Scotland — so you would be over the limit long before your BAC reaches zero. Use our calculator for a personalised estimate of your elimination time.

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, 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 high 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 — use our calculator to estimate when your BAC should be back to zero.

What is the margin of error for breathalyzers?

Breathalysers used in the UK are accurate but not perfect, and they carry a small margin of error. Police-approved evidential devices typically work within a tolerance of around ±2 micrograms per 100ml of breath, or roughly ±6mg per 100ml of blood. In practice, a reading of 35µg/100ml could reflect a true value somewhere between about 33 and 37µg/100ml.

This tolerance does not give drivers a safety buffer. If a roadside or station test shows you are over the legal limit, you can still be prosecuted — the margin is built into how the devices are calibrated and approved for use in court. Personal breathalysers sold to consumers are generally less accurate than police equipment and can drift over time, so they should be treated as a guide only. The safest course is never to drink and drive rather than to rely on a reading that sits close to the limit.

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