How much water do you really need?

Few wellness topics attract as many confident, contradictory claims as hydration. You have probably heard that everyone needs exactly eight glasses a day, or that you should drink until you are never thirsty. The truth is more relaxed: water needs vary from person to person, and the simplest approach is usually the most reliable.

The familiar "eight glasses a day" rule is a rough rule of thumb, not a strict prescription. How much you actually need depends on your size, how active you are, the weather and what else you eat and drink. On a hot day or after exercise you will naturally need more, while on a quiet, cool day you may need less. Treat any single number as a starting point rather than a target to hit exactly.

Your body is also good at telling you what it needs. For most healthy people, thirst is a useful guide — drinking when you feel thirsty and a little extra around activity covers a lot of ground. You do not need to force down water on a strict schedule to stay well hydrated.

It is worth remembering that water comes from more than your glass. Many foods, especially fruits, vegetables and soups, contain a surprising amount of water, and other drinks count too. This means your daily intake is spread across everything you eat and drink, not just the plain water you pour on purpose.

A practical way to stay on track is to make water easy to reach. Keeping a bottle on your desk, having a glass with each meal and taking a few sips when you take a break all add up without much thought. Small, steady habits tend to work better than trying to drink a lot at once.

If you are ever unsure whether you are drinking enough, pale, light-coloured urine is a common everyday sign that things are roughly on track. Beyond that, you can keep it simple: drink when you are thirsty, drink a bit more when it is hot or you are active, and let your body do the rest.