The short answer: most adults in the UK should aim for around 6 to 8 glasses of fluid a day. That’s roughly 1.5 to 2 litres. That's an average and not a rule carved in stone. Your body size, your age, how active you are, the weather, where you live and even what you eat all shift that amount up or down.
If you've ever felt confused by what you read online, you're not alone. There’s a lot of competing information out there on how much water you should drink. Maybe we can help clear it up.
Where the "6 to 8 glasses" guideline comes from
UK health bodies (including the NHS, the British Nutrition Foundation and the British Dietetic Association) generally recommend roughly 6 to 8 glasses of fluid per day for adults. The European Food Safety Authority (EFSA) puts it slightly more precisely at around 2 litres a day for women and 2.5 litres for men, including fluids from food.
That last point matters. You don't have to drink all of those glasses. Around 20–30% of your daily fluid intake typically comes from food. Think soups, fruit, vegetables, yoghurts, etc. Only the rest of it comes from what you drink.
Does it have to be plain water?
No. Water is a great choice because it has zero sugar and zero calories, but it's not the only thing that counts. Any drink (including sugary drinks) contributes to your daily fluid intake. The one exception is alcohol, which actually works against hydration because it makes you urinate more.
But what if plain water bores you? For many people that's a real barrier to drinking enough. Thankfully it’s solvable. A sugar-free flavour drop like a waterdrop® Microdrink turns plain water into something you'll actually reach for, without the sugar of a soft drink.
When you need more than the average
You'll need to top up your intake when you're:
- Exercising: you lose fluid (and electrolytes) through sweat
- In hot weather: the same applies on warm days or in heated offices
- Illness: fever, vomiting or diarrhoea drain fluids fast
- Pregnant or breastfeeding: the BDA recommends increasing fluids, especially in hot weather or when you're active, and choosing sugar-free or low-sugar drinks.
The easiest way to check: look, don't count
Counting glasses is fiddly. A far simpler way to check is the colour of your urine. A pale straw colour means you're well hydrated. Darker yellow is your body's signal to drink more. UK dietitians rate this as one of the most practical day-to-day checks you can do.
Can you drink too much water?
Yes, technically. Drinking extreme amounts in a short time, usually during endurance events, can dilute the sodium in your blood, which is dangerous. In everyday life this is less of a concern if you spread your intake out across the day.
FAQ
Is 2 litres of water a day enough?
For most UK adults, yes. Around 1.5 to 2 litres will be enough, with more on hot or active days.
Do tea and coffee count towards my water intake?
Yes. Tea and coffee both count towards your daily fluid total, so there's no need to track them separately from water. If you're pregnant, the NHS advises keeping caffeine under 200mg a day.
How do I know if I'm drinking enough?
Check your urine colour. Pale straw means you're hydrated; dark yellow means drink more.
Does drinking more water have health benefits?
Staying well hydrated supports important bodily functions such as energy and concentration.* We cover this in our guide to the benefits of drinking water.
*Water contributes to the maintenance of normal physical and cognitive functions. Drink at least 2.0 L water per day, from all sources, to obtain this effect. A varied, balanced diet and a healthy lifestyle are important.
This article is for general information and isn't medical advice.
