Is the Alcohol Units System Broken?

A recent study demonstrated that the quantity of alcohol consumed by people in the UK is under reported by almost half; that is to say that the difference between what people say they drink and the quantity of alcohol sold, varies considerably.

This will not come as great shock to people working in the licensed hospitality industry, drink industry, private security, emergency services or in the health authorities.

Ask a police officer or ambulance crew member how they interpret an answer to the question ‘how much have you had to drink’ when dealing with a drunk person and they will probably answer that they take the answer given and multiply it by three; this gives them a more realistic marker to work from.

The natural tendency for people to underestimate alcohol consumption, is exasperated by the floored systems which are currently in place to measure consumption. The government, health authorities, legal statute, drink industry, licensed retail / hospitality sectors, all quote statistics using different base measurement systems, which confuses public perceptions.

Strength of Alcoholic Drinks

We measure the strength of alcoholic drinks in the UK as a percentage of alcohol by volume (% abv); literally the percentage of alcohol in a volume of liquid.

For example; most gin is 40% abv, therefore 40% of the liquid in a bottle of gin is undiluted alcohol.

Recommended Levels of Alcohol Consumption

The government via the health authority provide us with guidance on the recommended level of alcohol consumption to avoid alcohol related health issues. This is set at different level for men and women due to physiological differences.

These limits are measured in Alcohol Units with the current recommendation set at:

Men 3 – 4 Units a day / 21 Units a week
Women 2 - 3 Units a day / 14 Units a week

Units of Alcohols

The unit system was set up over 25 years ago as a way of setting reasonable limits which were easy to understand and thus easy to interpret by consumers.

Units are calculated with the following equation:

% abv x volume of alcohol (ml) x 0.001 = No. of Units of Alcohol

When the system was introduced the drinks industry was very much less diverse and so units of alcohol were relatively straight forward:

  • Half Pint of Beer = 1 Unit of Alcohol
  • Small Glass of Wine = 1 Unit of Alcohol
  • Single Shot Spirits = 1 Unit of Alcohol

That was 25 years ago, since then the drinks industry, the licensed hospitality sector and the consumers of alcohol have all changed substantially.

Alcohol Products

The type of alcohol consumed is now very different to when the Units of Alcohol system was set up.

Beer - when the unit system was set up the most brands of beer were 3 - 4% abv and the product mix was much more weighted in favour of ales; this provides an explanation for a half pint of beer equalling 1 Unit of Alcohol, as it would have to have be 3.5% abv.

Most beer today, especially lagers, which are perceived by the public as ‘standard strength’ are in the region of 4% abv with ‘premium’ ranges and many bottled being closer to 5% abv.

It is really now only ‘standard’ ales which can be found in the 3.5% abv bracket (or the 1 unit per half pint), but even in this category there has been a move towards specialist and local varieties which often have higher percentage of alcohol by volume.

Wine & Champagne sales have exploded since the inception of the units of alcohol system, and this is especially true with the popularity of ‘new world wines’ which tend to have a higher % abv. Under the units of alcohol system, it was assumed that wine was on average 8% abv, which would mean a small glass (125ml) would be the equivalent of 1 unit of alcohol.

A quick glance at any supermarket shelf, will demonstrate that most wine is now in the region of 11 – 14% abv.

Spirits have largely stayed at the level we currently see of 40% abv and thus there has been no great change in the 1 unit consumed for every 25ml measure.

We have seen some fluctuation in the consumption patterns, with the popular ‘shot culture’ and cocktail options adding some confusion.

FABs & ‘Alco-pops’ present a whole sector which was never really covered by the units of alcohol system, as they appeared on the market after its inception.

Weights & Measures Act

While the type and strength of drinks have changed over the years the Weights and Measures Act has remained relatively constant:

Beer & Cider (On-Sales) – Draught products must be sold in measures of half an imperial pint (284ml) or multiples thereof.

Wine (On-Sales) – Must be sold in 125ml (Small Glass) or 175ml (Large Glass) or multiplies thereof.

The public’s perception and the perception of many in the licensed hospitality sector, is that a small glass of wine is 175ml and a large glass of wine is 250ml.

The 250ml measure is permitted, but legally it is effectively a double ‘small glass’. In most people’s mind the 125ml glass is an unused legal necessity, rather than a measure their customers understand or would expect to be served in.

Spirits (On-Sales) – Must be sold in either 25ml or 35ml or multiples thereof; unless three or more liquids are mixed together, in a cocktail for example.

Off-Sales - Pre-packaged products can be sold in different quantities, making cans and bottles of all shapes and sizes acceptable, providing they are measured and labelled with the % abv & volume in ml.

Many in the drinks industry have now voluntarily added the number of units of alcohol to the product labelling, on drinks produced for the off-sales market.

Free Pour – The significant increase in consumption of alcohol at home over recent years, where free-pour measures can be assumed to be double or treble those closely measured by law at the point of sale, should be reason enough for the government to look at policies which encourage people back into pubs, bars and restaurants. This is a problem is exasperated by the ‘pre-loading’ culture.

Counterfeit Alcohol - The vast illegal trade in alcohol, which accounts for billions of pounds worth of untaxed or counterfeit alcohol sold by organised criminals should also not be ignored. Those producing counterfeit alcohol are unlikely to measure the % abv or for that matter the quality of anything that goes into the production.

Confusing Maths

If this is not all confusing enough for those working in the industry, imagine the confusion and therefore disinterest by the public, different messages, different measure and differing quantities, making it virtually impossible to keep track.

Ask the average person ‘how much more alcohol there is in a beer with 4% abv and one which is 5% abv; and the vast majority inevitably answer 1%. The right answer is a staggering 25% more alcohol.

For a pint of beer of 4% abv – 4 x 568 x 0.001 = 2.27 Units

For a pint of beer of 5% abv – 5 x 568 x 0.001 = 2.84 Units

Therefore the 5% abv pint of beer contains an additional 0.57 units of alcohol, which equates to a 25% increase in the number of units and therefore a 25% increase in the actual consumption of alcohol.

If we look at the additional 0.57 units of alcohol in the context of the government recommendation, it equates to 22% or 17% of the recommended daily allowance for women and men respectively.

If we add to this confusion, the misunderstanding surrounding measurements, the situation deteriorates further.

An Example - someone goes to a restaurant and orders a small glass of wine, which they assume is 1 unit of alcohol.

What they will probably receive is a 175ml glass of wine with an average 12.5% abv.

175 x 12.5 x 0.001 = 2.2 Units

This is a staggering 120% More Alcohol than they had assumed they were consuming; according to the popular rhetoric of a small glass of wine being 1 unit of alcohol.

This would account for a considerable number of the so called ‘Lost Units’.

A New System

We cannot revert back to the days when products ranges were limited or try to recapture old drinking habits; alcohol consumer’s habits have changed and they will not turn back the clock.

The government seems to believe that a Minimum Price per Unit is the answer and while it will in my opinion make a difference, it is not the final solution. The one-size-fits-all approaches they favour, does not address the confusion their own guidelines create.

Those people with significant alcohol addictions require a different solution to those who drink a little too much for their own health and the majority who drink responsibly, should where possible, not be unduly restricted.

Many people may be able to quote the government’s recommended daily allowance when it comes to alcohol consumption, but most have little idea of the unit of alcohol there are in the drinks they consume or worse, they substantially underestimate the number of units in their drinks.

The Units of Alcohol system is really no longer fit for purpose, there does need to be some adjustment of people’s alcohol consumption, but this will need to reflect current drinking habits and trends, rather than the pursuit of prohibition policies which are proven to be ineffective.

A system which works will rely on better labelling of products, more transparent marketing, better education for those selling alcohol and those consuming alcohol, all of which will go some way to resolving the misconceptions.

The government must give up or substantially reform the current Units of Alcohol System, where the theory doesn’t reflect reality. At best it’s ineffective at worst it is adding to the problem.


Author - Peter Mayhew is the Managing Director of Beyond the Blue Training & Consultancy. He delivers training courses and provides expert opinion on alcohol & entertainment licensing, to individuals, organisations and public bodies. Peter is a frequent contributor to industry publications.

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