Britons massively underestimate the amount of alcohol they drink, new study reveals

Britons massively underestimate the amount of alcohol they drink, new study reveals

Britons are in the dark about how much alcohol they are actually consuming, according to research conducted by Direct Line Motor Insurance.

The survey, which quizzed 2,000 UK adults about their drinking habits, found that almost three-quarters of people underestimate the amount of wine in a 250ml glass.

In fact, 70% of people believed that a large glass of wine (a third of a bottle) was actually the equivalent of a small or medium glass.

And only 22% of people were able to correctly identify a double measure of gin.

The results of the survey have highlighted concerns that Britons are causing themselves silent harm, by over-indulging with larger measures of alcohol at home.

Andrew Misell, Director at Alcohol Change UK, said of the findings: “We’ve seen a big shift in drinking habits in recent years with more and more of us drinking at home.

“But, as this study has shown, many people are unsure of the size of the drinks they’re pouring themselves and often underestimate how much they’re having. This can lead to them drinking more than they intend without realising.

“If you’re drinking at home, it’s smart to get in the habit of checking the units in your drinks, keeping a running tally, and staying under 14 units a week.”

Know your units

So, just how many units of alcohol are there in your favourite tipple?

The NHS recommends that men and women do not drink more than 14 units of alcohol per week. However, this latest research shows that many people are unaware of just how much they are drinking.

The long-term impact of alcohol misuse is well documented, with physical and mental health issues such as depression, high blood pressure, problems with the immune system and liver damage all linked to heavy alcohol use.

If you are someone who enjoys an occasional drink at home or on social occasions, it is important to understand how many units of alcohol there are in different drinks.

The below table provides an overview of different alcoholic beverages and the approximate number of units in each:

Drink Number of units
Small, single shot of spirits*
*Gin, rum, vodka, whisky, tequila and sambuca
1 unit
Alcopop (275ml) 1.5 units
Small glass of wine (125ml) 1.5 units
Standard glass of wine (175ml) 2.1 units
Large glass of wine (250ml) 3 units
Bottle of lager, beer, or cider (330ml) 1.7 units
Can of lager, beer, or cider (440ml) 2.4 units
Pint of low-strength lager, beer, or cider (ABV 3.6%) 2 units
Pint of higher-strength lager, beer, or cider (ABV 5.2%) 3 units

Managing your alcohol intake this Christmas

The festive season can be a difficult time for many when it comes to managing alcohol consumption, with drinking practically encouraged at Christmas parties and family events.

However, there are a few steps you can take to manage your alcohol intake this Christmas and into the New Year.  

In addition to keeping track of the number of drinks you have had, and being mindful of the number of units in each drink, it can also be helpful to:

  • Choose smaller drinks – perhaps swapping a large glass of wine for a small glass
  • Avoid drinking every day – aim for a set number of alcohol-free days each week and stick to them  
  • Avoid having alcohol at home – having alcohol within easy reach can make limiting your consumption more difficult. Try alcohol-free options instead, like mocktails, to quench your thirst
  • Team up with a friend – it can be helpful to have support when you are trying to reduce how much you drink. Consider teaming up with a friend to reduce your alcohol intake. This can help ensure you stick to your goals

For individuals struggling with more severe alcohol addiction, reducing alcohol intake, or quitting drinking altogether can be extremely challenging, meaning that professional support is required.

Alcohol testing you can trust

With over 15 years’ experience providing accredited laboratory testing for members of the public, the legal sector, and the workplace sector, we are well placed to support you with alcohol testing to meet a range of needs.

We offer a full alcohol testing service using a variety of methods including point-of-care breath testing, blood analysis, nail clippings, hair analyses and alcohol monitoring using SCRAM CAM®

Here are a few examples of who might need an alcohol test:

  • Members of the public who require a test for official matters, such as an industrial tribunal, or private contractors who need an alcohol test before starting work
  • Legal professionals and social workers overseeing child protection cases
  • Concerned parents who want to find out if their child is misusing substances, in order to seek support
  • Private individuals who require a test for legal matters such as divorce proceedings or custody disputes
  • Businesses looking to introduce a substance misuse policy, or update their existing policy regarding testing requirements

For more information, contact our friendly and discreet Customer Services team on 0333 600 1300 or email  

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