UK Drink Drive Limit Calculator

Calculate your blood alcohol content and check if you’re safe to drive

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0.00 0.08 (UK Limit) 0.20+

⚠️ Important Legal Notice

This calculator provides estimates only. The legal drink drive limit in England, Wales and Northern Ireland is 80mg of alcohol per 100ml of blood (0.08% BAC). In Scotland, the limit is lower at 50mg per 100ml (0.05% BAC). Individual responses to alcohol vary significantly. The safest option is never to drink and drive.

Complete Guide to UK Drink Drive Limits

UK Legal Limits

England, Wales & Northern Ireland:

  • 80mg alcohol per 100ml blood
  • 35 micrograms per 100ml breath
  • 107mg alcohol per 100ml urine

Scotland:

  • 50mg alcohol per 100ml blood
  • 22 micrograms per 100ml breath
  • 67mg alcohol per 100ml urine

How Alcohol Affects You

Blood alcohol content depends on several factors:

  • Body weight and composition
  • Gender (women typically have higher BAC)
  • Food consumption
  • Rate of consumption
  • Medication and health conditions
  • Age and metabolism

Alcohol Units Guide

Standard UK drink units:

  • Pint of beer (4% ABV) = 2.3 units
  • Glass of wine (175ml, 12% ABV) = 2.1 units
  • Single spirit (25ml, 40% ABV) = 1 unit
  • Alcopop (275ml, 5% ABV) = 1.4 units

Penalties for Drink Driving

UK drink drive penalties include:

  • 12-month minimum driving ban
  • Unlimited fine
  • Up to 6 months imprisonment
  • Criminal record
  • Higher insurance costs
  • Possible job loss

Frequently Asked Questions

How long after drinking can I drive?
Alcohol leaves your system at approximately one unit per hour. However, this varies by individual. A good rule is to wait at least one hour per unit consumed, plus an extra hour for safety.
Can I speed up alcohol elimination?
No. Coffee, cold showers, or exercise cannot speed up alcohol metabolism. Only time eliminates alcohol from your system.
What if I’m just under the limit?
Even if you’re under the legal limit, you can still be prosecuted if your driving is impaired. Police can charge you with driving whilst unfit through drink if your ability is compromised.
Are breathalyser tests accurate?
Professional police breathalysers are highly accurate when properly calibrated. Home breathalysers can provide estimates but shouldn’t be relied upon for legal compliance.
What about morning after drinking?
Many drink drive arrests occur the morning after. Alcohol can remain in your system for many hours after you stop drinking, especially after heavy sessions.

References

  1. Department for Transport. (2023). Reported road casualties in Great Britain: drink drive accidents and casualties. Crown Copyright.
  2. GOV.UK. (2023). Drink-drive limits. Retrieved from gov.uk/drink-drive-limit
  3. National Health Service. (2023). Alcohol units. NHS Choices.
  4. Road Safety Authority. (2023). The facts about drink driving. Crown Copyright.
  5. Widmark, E. M. P. (1981). Principles and applications of medicolegal alcohol determination. Biomedical Publications.
  6. Watson, P. E., Watson, I. D., & Batt, R. D. (1981). Prediction of blood alcohol concentrations in human subjects. Journal of Studies on Alcohol, 42(7), 547-556.

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