How Much Water Should You Drink a Day?

Water is one of those simple health habits that is easy to overthink. The short answer is that many adults do well on around 6 to 8 glasses, roughly 1.5 to 2 litres a day, but this is a guide and not a strict rule. Your own needs go up and down depending on your body, how active you are, and the weather. Below is a clear, beginner-friendly breakdown so you can stop counting and start trusting a few easy signals instead.

What is the common guidance, and is it a rule?

You have probably heard the "6 to 8 glasses a day" advice, which works out to roughly 1.5 to 2 litres for many adults. UK health guidance points to this kind of range, and it is a sensible starting point. The important thing to know is that it is a guide, not a fixed target you must hit to the millilitre. There is nothing magic about exactly 2 litres, and the old "8 glasses of plain water" idea was never based on strong science.

In practice, your body is good at managing fluid. Thirst is a reliable signal for most healthy people, and your kidneys adjust how much water they hold on to or release. So treat the range as a friendly benchmark, then adjust up or down based on how you feel and the situations in this article.

What affects how much water you need?

Several everyday factors push your needs higher or lower. The main ones are:

• Body size: larger bodies generally need more fluid than smaller ones.
• Activity: exercise makes you sweat, so the more you move, the more you replace.
• Heat and climate: hot, humid or very dry conditions all raise your needs.
• Health: a fever, vomiting or diarrhoea increase fluid loss, so you need to drink more to keep up.
• Pregnancy and breastfeeding: both raise daily fluid needs, so aim a little higher than usual.
• Altitude and air travel: dry cabin air and high places can dry you out faster.

Here is a rough guide to how much extra you might want in common situations. These are general ballparks to help you think, not precise prescriptions.

Do other drinks and foods count?

Yes. A common myth is that only plain water counts, but that is not true. Almost everything you drink adds to your daily fluid, including water, milk, squash, tea and coffee. Tea and coffee in normal amounts still count toward your total, even though caffeine has a mild diuretic effect. Lower-sugar options are better for your teeth and overall health, so plain water is still the smart everyday choice.

Food matters too. Water-rich foods like cucumber, tomatoes, oranges, melon, soups and yoghurt all add up over a day, and for many people they quietly cover a meaningful share of their intake. So if you eat plenty of fruit, vegetables and soups, you may need a little less from drinks alone.

How can you tell if you are hydrated?

You do not need an app or a strict counter. A few simple signals tell you most of what you need to know.

The easiest habit is to glance at your urine colour and drink to thirst. Pale straw is the target. If you are often thirsty, getting headaches, or feeling unusually tired, a glass or two more across the day usually helps.

How should you hydrate around exercise?

Training adds to your needs because you lose fluid through sweat. A simple approach works for most people who run, lift or do HIIT:

• Before: drink a glass or two of water in the couple of hours before you train so you start topped up.
• During: sip when you feel thirsty. For short sessions, plain water is plenty.
• After: rehydrate with water after you finish, and have a little more if the session was long or you were dripping with sweat.

For longer or very sweaty sessions, usually over an hour, electrolytes can help. When you sweat a lot you lose salts as well as water, so an electrolyte drink or a pinch of salt with your fluids helps you absorb and hold on to what you drink. For shorter everyday workouts, you almost never need anything fancy.

Can you drink too much water?

It is possible, though rare for most people. Drinking very large amounts of water in a short time can dilute the sodium in your blood, a condition called hyponatraemia, which can be serious. This mostly affects endurance runners who overdrink during very long events, not someone topping up normally through the day. The practical takeaway is simple: spread your fluids across the day, do not force huge volumes in one go, and let thirst guide you rather than chasing a big number.

What are simple habits to drink enough?

Small routines make this effortless. Try a few of these:

• Keep a refillable bottle on your desk or in your bag so water is always within reach.
• Have a glass with each meal and one when you wake up.
• Drink a little before, during and after training.
• Flavour water with lemon, cucumber or mint if plain water feels boring.
• Eat plenty of water-rich fruit and vegetables, which top you up without trying.
• Check your urine colour now and then as a quick reality check.

One honest note on tracking: Edge builds and tracks your weekly running, strength and HIIT plan, but it does not track hydration or nutrition, so treat this article as general guidance only. If you have a kidney or heart condition, or you want a personalised plan for hydration or nutrition, follow medical advice and speak to a doctor or a registered dietitian, who can tailor the right amounts to you.