🚗 What Is the UK’s Legal Drink Driving Limit?

In the UK, drink driving laws are strictly enforced and can carry serious penalties. The limit is measured as Blood Alcohol Concentration (BAC) — that is, how much alcohol is in your blood when you're stopped.

📏 UK Drink Driving Limits

Region Breath (mcg/100ml) Blood (mg/100ml) Urine (mg/100ml)
England, Wales, Northern Ireland 35 mcg 80 mg 107 mg
Scotland 22 mcg 50 mg 67 mg

🔍 Scotland has stricter limits than the rest of the UK — and lower tolerance for drivers with any alcohol in their system.

🍷 How Many Units Can You Drink Before Driving?

This is the most common question — and the most misunderstood. The number of alcohol units it takes to reach the legal limit varies by person.

⏳ What Is a Unit of Alcohol?

  • 1 unit = 10ml (8g) of pure alcohol

Drink Amount Alcohol Units
Beer (pint) 568ml @ 5% 5% ABV ~2.8
Wine (glass) 175ml @ 13% 13% ABV ~2.3
Spirits (single) 25ml @ 40% 40% ABV 1

👉 Most people exceed the legal limit with 2–3 drinks, depending on:

  • Body weight

  • Sex

  • Food intake

  • Time between drinks

🚫 The safest amount of alcohol to consume before driving is: zero.

🧮 Should I Use a Drink Driving Limit Calculator?

Drink driving calculators online can help estimate your BAC, but they are not 100% accurate and should never be used to determine whether you're safe to drive.

For safer alternatives:

  • Use a personal breathalyser

  • Wait 1–2 hours per unit

  • Or don’t drink at all if you plan to drive

⚠️ Drink Driving Penalties in the UK

First Offence (England & Wales):

  • 🚔 Minimum 12-month driving ban

  • 💰 Fine up to £5,000

  • 🔒 Up to 6 months’ imprisonment

  • 📉 Criminal record and increased insurance premiums

Aggravated or Repeat Offences:

  • Driving while heavily intoxicated

  • Causing death by drink driving
    → Prison sentences up to 14 years

Scotland follows similar guidelines, but courts have a lower threshold for enforcement due to stricter BAC levels.

👨‍⚖️ Zero Tolerance for Some Drivers

The UK may allow small BAC levels, but new drivers, professional drivers, and drivers under 25 are highly scrutinised. In some cases, insurance policies require complete abstinence.

🚦 Legal & Safe Alternatives

  • Designated driver

  • Taxi or ride-hailing apps

  • Public transport

  • Non-alcoholic options

Don’t risk your licence, safety, or someone else’s life.

✅ Conclusion

Knowing the drink driving UK limit is essential, but the only truly safe amount of alcohol to consume before driving is none. The penalties are severe, and the margin for error is too small to risk.

If you're asking, “Can I drive after one drink?” — it's best to wait or walk. 🛑

Sources

  1. GOV.UK – Drink-driving penalties – https://www.gov.uk/drink-driving-penalties

  2. NHS – Alcohol units explained – https://www.nhs.uk/live-well/alcohol-advice/calculating-alcohol-units/

  3. Drinkaware – How much is too much? – https://www.drinkaware.co.uk/facts/drinking-and-driving/the-drink-drive-limit

  4. Police Scotland – Drink and drug driving – https://www.scotland.police.uk/advice-and-information/road-safety/drink-and-drug-driving/

  5. Road Safety GB – Drink Driving Facts – https://roadsafetygb.org.uk/safer-drivers/drink-driving/