A poll, of 2,000 adults, found 16% believe they can count an alcoholic drink as one of their recommended eight glasses of water.
More than one in five also admitted they have no idea how much water they should be drinking, with just 42% aware that around two litres, or eight glasses is the recommended amount.
As a result of the confusion, the poll, by Robinsons, found the average adult only consumes just 3-and-a-half glasses of water, with one in twenty claiming to not drink any water at all on an average day.
The study, conducted by Onepoll for Robinsons, found that one in five Brits can often go eight hours or more between having a drink of water. And more than one in five don't like the taste of water.
But of the 31% who drink more water at home, than they do at work, 26% put it down to simply forgetting to drink while they are doing their job.
Two thirds say they are usually two busy to think about getting a drink.
It's not just adults who are missing out though as of the parents who took part in the poll, 36% admitted they don't know how much water their children should be drinking.
Another three in ten said they find it difficult to get their children to drink enough, with 42% of those saying their kids find the taste of water 'boring.'
Independent Dietitian, Helen Bond added "As well as feeling thirsty, the taste, colour and flavour of drinks is what often encourages us to drink more often. So, one of the easiest ways to make sure you and your family are consuming the recommended adequate intakes of water is to drink from a variety of different sources. Different tastes provided by drinks such as no added sugar squash, can make drinking water enjoyable for both adults and children."
"Our bodies are made up of about 60 per cent water, so staying refreshed is important in helping our brain and bodies function well - whatever age you are!"
To find out more about enjoying drinking more water with Robinsons, visit www.robinsonssquash.co.uk/enjoymorewater, find us on Facebook or tweet us @DrinkRobinsons using the hashtag #EnjoyMoreWater
Do you drink the recommended amount of water each day?