Standard drinks and Guidelines Explained

Do you know how to measure alcohol? It depends on your drink. Discover how much a "unit" of alcohol is and how it relates to drinking guidelines.
How can you measure the amount of alcohol you drink?
Standard drinks and Guidelines Explained

A standard drink is a measure of the alcohol in your drink. It’s the same for beer, wine and spirits, and is expressed as grams of ethanol (1). In Ireland, a standard drink contains ten grams (2).

The purpose of a standard drink is to provide consistency across beverage types and help translate the science behind drinking and health into something easily understood. This is important for providing drinking guidelines and advice. The HSE guidelines are to drink less than 11 standard drinks a week for women and less than 17 standard drinks a week for men, spread out over the week, with 2-3 alcohol-free days per week and to drink no more than six standard drinks on any one occasion to minimise any health risks from alcohol (3).

Standard drink sizes are different across countries, but they always ensure the amount of alcohol is the same in any beverage

Infographic explaining how much alcohol is in a standard drink in Ireland, as well as how many standard drinks are in common drinks beer, wine and spirits
Infographic explaining how much alcohol is in a standard drink in Ireland, as well as how many standard drinks are in common drinks beer, wine and spirits

Not all countries use the same standard drink size as Ireland (1). Nevertheless, in each case, the same measure applies whether you’re drinking beer, wine or spirits.

Some places, like the UK, also refer to a ‘unit’ rather than a ‘standard drink’.

For example:

  • A standard unit in the UK contains 8 grams of ethanol
  • In Australia and France, the standard is 10 grams
  • A Mexican standard drink contains 13 grams
  • There are 14 grams of ethanol in a standard drink in the US, Argentina and Chile

'Standard drink' can help you understand drinking guidelines

It’s true that a standard drink doesn’t always translate into how drinks are actually served. For example, many cocktails contain several different spirits or are mixed with wine or champagne, so they’ll most likely contain more alcohol than in a standard drink. Also, since wine comes in different strengths, and glasses are available in different sizes, the amount of alcohol you drink may not be standard. This is especially true if you’re at home and top up your glass before you’re finished.

However, a standard drink is still a useful concept. Since the concentrations of drinks are different, a unit ensures that the amount of ethanol in a serving is always the same. This is important for sharing information about drinking and its effects on your health.

Using a standard drink allows for guidance on levels of drinking, regardless of whether the drinks are spirits, wine or beer. Plus, advice is generally given in terms of the number of standard drinks it’s best not to exceed in a day or a week, or on an occasion.