More than two-thirds of beer and wine sold in pubs and bars is short-measured, costing the average consumer about £115 a year, according to research.

Trading standards officers visited 77 venues across the UK, finding 96 short measures out of 137 test purchases, meaning approximately 70% had less of the drink than had been declared or paid for.

Meanwhile, the average price of a bottle of red wine has increased 8% in the last year, according to the Office for National Statistics, while a pint of lager has gone up by 5.6%.

John Herriman, the chief executive of the Chartered Trading Standards Institute (CTSI), said: “While this is a snapshot, it is the first time that we have been able to build a national picture of how widespread short measuring of alcoholic drinks are, and the potential detriment to the average consumer of around £115 every year suggests there is the need for more comprehensive research.”

He said the research should be across a broader spectrum of consumer goods, not just alcoholic drinks.

A short measure means the beer or wine the customer receives is less than the quantity required by the Weights and Measures (Intoxicating Liquor) Order 1988. These quantities vary depending on the drink served, but include pints, half-pints for beer and 175ml glasses for wine.

Errors found by CTSI included measuring instruments not being used correctly or the wrong ones being used. It said guidance was offered to businesses where appropriate.

Out of the short measures, 41 were at a deficit of 5% or more – 29% of all the 137 drinks tested. When broken down by drink, the study found that 86% of beer was short measured and 43% of wine.

The average deficit for beer was 4% and for wine it was 5%. For the average beer drinker, this equates to a loss of £1.70 a week, or £88.40 a year. For a wine drinker in the UK it is £2.20 a week, or £114.40 a year.

The largest short measure was 15%, found on a 175ml glass of wine in Walsall that cost £3.20.

Public polling by the CTSI also found that more than a third (35%) of people felt the head of the beer should not be included in the pint measure.

Jess Phillips, the Labour MP for Birmingham Yardley and CTSI vice-president, said: “The cost of living means people can hardly afford a drink … A short measure cheats us all, but affects those worst off the hardest.”

In 2021 the British Beer and Pub Association reported that on-trade sales of beer alone generated £5.7bn in revenue, the equivalent at the time of 1.4bn pints a year, or 26m pints a week. With today’s prices, a 4% deficit in each pint would equate to £264m in potential consumer detriment, CTSI said.

While setting up this study, CTSI discovered that many local authorities who wished to participate were unable to do so as they did not have the basic equipment needed to measure beer and wine. The CTSI said this was a stark illustration of the pressure that local authorities were under.

The national fieldwork was undertaken by eight local authorities including Aberdeenshire, Essex and Maidenhead, as well as Northern Ireland Trading Standards.