A simple daily guide
Common guidance lands around 1.5–2 litres of drinks a day for many adults, but needs vary with body size, activity, weather, pregnancy and illness. Using body weight (~33 ml/kg) personalises it — a 70 kg person might aim for roughly 2.3 litres of total fluid.
Do other drinks count?
Yes. Water, milk, tea and coffee all contribute to your fluid intake, and water-rich foods like fruit and vegetables help too. Sugary and alcoholic drinks hydrate but bring downsides, so water is still the best default.
Signs you need more fluid
Dark-yellow urine, thirst, tiredness, headache and dizziness can all signal you need to drink more. Pale, straw-coloured urine is a good everyday sign you’re well hydrated.