Many young people underestimate how much alcohol they drink even if they have some knowledge of the government's guidelines on sensible consumption, a study says.
Researchers said their results suggest that young people do not have the knowledge or skills to keep their drinking within the set guidelines.
The University of Sussex-led study, which is published in Drug and Alcohol Review, surveyed 18 to 25-year-olds about their knowledge and beliefs on safe drinking.
People who took part in the study were asked to pour their usual measure of wine, beer or vodka followed by what unit they believed it to be.
Nearly two-thirds underestimated the unit content of the drinks they poured, researchers said. The government's daily unit guidelines are up to two to three units for a woman and up to three to four units for a man.
A pint of lager or cider with a 5% alcohol content contains three units. Two small (125ml) glasses of wine with a 12% alcohol content are another three units.
Fewer than half of participants in the study gave the correct answer to five out of seven questions testing knowledge of the government's alcohol consumption guidelines.
But most knew the recommended daily units for men and women.
Research leader Dr Richard de Visser, a senior lecturer in psychology, said: "Our results indicate that young people tend not to possess the knowledge or skills required to drink alcohol in accordance with government guidelines.
"Using drink-pouring tasks as part of this education could promote better understanding of alcohol units and more accurate reporting of alcohol consumption."
A Department of Health spokeswoman said: "Drinking too much can lead to serious diseases, such as heart disease, cancer and stroke, later in life, so it's really important that we help young people to understand how much they're drinking.
"Earlier this month we launched a new Change4Life campaign about alcohol. It gives us all advice on the health harms and aims to help people who are drinking a bit more than they should to cut down.
"Our forthcoming alcohol strategy will set out our plans on how to deal with the problems and harms alcohol causes."
The NHS recommends that men should not regularly drink more than three to four units of alcohol a day and women should not regularly drink more than two to three units a day.
Drinking heavily regularly one or two days a week can also harm your long-term health, the NHS says.