For most healthy adults in the UK, a good general target is 6–8 cups or glasses of fluid a day , which is roughly 1.5–2 litres, including water, tea, coffee, and other sugar‑free drinks. Your ideal amount can be higher or lower depending on your body size, how active you are, and things like heat, illness, pregnancy, or breastfeeding.

Core NHS-style guidance

  • UK government advice says to aim for 6–8 drinks a day, and this can include water, lower‑fat milk, and sugar‑free drinks such as tea and coffee.
  • Many UK health organisations describe this as around 1.5–2 litres per day for a typical adult, though some research suggests 1.5–1.8 litres is often enough when you include water from food.

Simple way to personalise it

  • A common practical rule is about 35 ml of water per kilogram of body weight (for example, around 2.5 litres a day if you weigh 72 kg), adjusted up or down for your activity and climate.
  • Professional dietetic guidance in Europe often quotes around 2,000 ml from drinks for men and 1,600 ml for women as a baseline, not counting extra needs for exercise, hot weather, or pregnancy.

When you might need more

  • You generally need more fluid if you are very physically active, work in a hot environment, are pregnant or breastfeeding, or are recovering from illness with fever, vomiting, or diarrhoea.
  • In those situations, drinking to thirst plus ensuring your urine stays a pale straw colour is a practical way to avoid both dehydration and overdrinking.

Signs you’re drinking the right amount

  • Pale yellow, clear urine most of the day is a good sign that hydration is about right; very dark, strong‑smelling urine can signal you need more fluid.
  • Feeling clear‑headed, not excessively thirsty, and not needing to rush to the toilet constantly are everyday clues that your intake is in a comfortable range.

Quick daily checklist (UK context)

  • Aim for 6–8 drinks spread through the day, making water your main choice.
  • Let thirst and urine colour guide you, and increase how much you drink if you are exercising, it’s hot, or you are unwell.

Information gathered from public forums or data available on the internet and portrayed here.