A trend to serving wine in larger glasses has added to public confusion over how much alcohol is safe to drink, the government said on Monday.
Nearly four out of five drinkers were unaware that a large glass of wine contains three units of alcohol - the maximum recommended daily limit for women, a Department of Health survey found.
It released the findings as it launched a national advertising campaign - Know Your Limits - to promote alcohol awareness.
"Glass sizes have grown larger and the strength of many wines and beers has increased, so it's no wonder some of us have lost track of our alcohol consumption," said Public Health Minister Dawn Primarolo.
The government is under pressure to combat rising levels of binge drinking, particularly by young people, blamed for aggravating anti-social behaviour and violence.
The Department of Health is spending 6 million pounds on its awareness campaign, and the Home Office will follow up with a 4 million pound campaign against binge-drinking next month.
But researchers questioned how much notice young people would take.
Bath University psychologist Andrew Bengry-Howell said he had found that young people took no account of unit limits.
"Monitoring your drinking in that way went totally against their objective, which was primarily to go out and get drunk," he told the BBC.
The government says women should drink no more than 2-3 units of alcohol a day, while the daily limit for men is 3-4 units, the equivalent of 1.5 pints of medium strength beer.
Its survey found that three-fifths of women were aware of their guideline, compared to just half of men.
The government used to publish recommended weekly limits, but changed to a daily measure after it found many people storing up their quota for the weekend.
It said drinkers regularly downing more than the advised limit greatly increase their risk of contracting illnesses such as liver disease, mouth cancer and stroke.
The awareness campaign includes a website - www.nhs.uk/units - with a downloadable alcohol units calculator.
