Alcohol units

Alcohol units tell you how strong a drink is. In Northern Ireland, one unit is 10ml or eight grammes of pure alcohol. There are health risks to regular drinking and drinking too much. If you drink alcohol, check the medical guidelines about limiting the units you drink each week.

What an alcohol unit shows

Alcoholic drinks have different strengths.  The number of units in one drink is based on the quantity of drink and the alcohol strength. One unit is 10ml or eight grammes of pure alcohol. Most adults can process this amount of alcohol in an hour.

Alcohol units in other countries

An alcohol unit is not a standard measurement. In other countries, one unit might contain more pure alcohol. 

Alcohol limits and unit guidelines

Published by the UK’s Chief Medical Officers, the low risk drinking guidelines are for men and women aged over 18 years who drink alcohol. The medical guidelines explain low risk drinking but don’t mean drinking alcohol is safe.

The medical guidelines give advice on:

Limiting weekly alcohol units

If you drink heavily on two or more occasions each week, you increase your risk of death from long-term illness or injuries.

To reduce the health risks from drinking alcohol:

  • don't drink more than 14 units a week regularly
  • spread your drinking over three or more days if you regularly drink 14 units a week
  • reduce your drinking and have several alcohol-free days each week

Fourteen units is equal to:

  • six pints of average strength beer
  • ten small glasses of low strength wine

Alcohol units in drinks

Compare alcohol units in different quantities of drinks:

  • a pint of strong beer has three units of alcohol
  • a pint of low or medium strength beer has over two units
  • a large glass of wine has three units
  • a standard glass of wine or pub bottle of wine has over two units
  • a small glass of wine has one and a half units

Glass sizes

Check how much alcohol different sized glasses can hold:

  • a pint holds 568ml 
  • a small wine glass holds 125ml
  • a medium wine glass holds 175ml
  • a large wine glass holds 250ml

Single drinking session

Adults who drink alcohol shouldn’t save up their units for a single drinking session.

To reduce the health risks from a single drinking session, the medical guidelines recommend:

  • limiting the amount of alcohol you drink on any occasion
  • drinking more slowly, drinking with food and swapping some alcoholic drinks for water
  • avoiding risky behaviour, for example rounds or shots
  • socialising with people you know will get you home safely

Drinking alcohol during pregnancy

There are no safe limits for drinking alcohol when you’re pregnant. Alcohol is harmful to your health and your unborn child’s health.

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