Water Intake Calculator: How Much Water Should I Drink a Day?
Weigh yourself before and after; each kg is about 1 litre of sweat to replace
11.8 glasses of 250 ml
- Daily target from drinks
- Extra to replace sweat
These are the National Academies' reference intakes for healthy adults in temperate climates. In Singapore's heat and humidity, outdoor work or sport raises the need further; let thirst guide you. If you have a kidney or heart condition, or a fluid limit, follow your doctor.
Drink about
3.0 litres
- Total water (drinks + food)
- 3.7 L
- From drinks (about 80%)
- 3.0 L
- From food (about 20%)
- 0.7 L
How this works
The daily target is the Adequate Intake of total water set by the US National Academies (Institute of Medicine) in its 2004 Dietary Reference Intakes: 3.7 litres a day for adult men and 2.7 litres for adult women, 3.0 litres in pregnancy and 3.8 litres while breastfeeding. Total water counts everything: plain water, other drinks including tea and coffee, and the water in food.
About 80% of total water comes from drinks and 20% from food, so the drinks figure is 80% of the target, shown in 250 ml glasses. The reference values are set for healthy people in temperate climates; the National Academies notes that people who are very active or live in hot climates may need more, and that very active people in constant heat often need 6 litres or more.
For exercise, weigh yourself before and after: each kilogram lost is roughly a litre of sweat that the target above does not include. Thirst is a reliable guide for most healthy people. People with kidney, heart or liver conditions, or on a fluid limit, should follow their doctor's advice instead.
FAQs
How much water should I drink a day in Singapore?
About 3 litres from drinks for men and about 2.2 litres for women, which is 80% of the National Academies' total water targets of 3.7 and 2.7 litres. In Singapore's heat, or when you exercise, you need more to replace sweat.
Is 8 glasses of water a day enough?
Eight 250 ml glasses is 2 litres, a little under the 2.2 litres of drinks a typical woman needs and well under the 3 litres for a man. Food, tea, coffee and other drinks count towards the total too.
How much water should I drink after exercise?
About 1 litre for every kilogram of body weight lost during the session, on top of your daily target. Weigh yourself before and after a run or game to see how much you sweated.
Does coffee count towards water intake?
Yes. The National Academies' total water figures include all beverages, including caffeinated drinks, as well as the water in food.