Daily Water Intake Calculator

The base formula multiplies your body weight in kilograms by 0.033 to get litres per day. For example, a 70 kg person needs approximately 2.3 litres as a baseline. This is then adjusted for activity level, climate, and other factors.

Singapore's tropical climate with average temperatures of 27-31°C and high humidity (80-90%) causes increased perspiration, even with sedentary activity. It is recommended to add approximately 0.5 litres to your base water intake to compensate for increased sweat loss in the tropical environment.

Common signs of dehydration include dark yellow urine, thirst, dry mouth, fatigue, dizziness, headache, and reduced urine output. In Singapore's heat, you can become dehydrated faster than you realise. A good indicator is urine colour — pale straw yellow indicates adequate hydration.

Exercise increases water needs significantly. Light exercise (30 minutes) adds about 0.35 litres, moderate exercise (1 hour) adds about 0.5-1 litre, and intense exercise (1+ hours) can require an additional 1-2 litres. In Singapore's heat, outdoor exercise requires even more hydration.

Yes. Despite the popular belief that caffeine causes dehydration, research shows that moderate amounts of coffee and tea provide net positive hydration. The diuretic effect of caffeine is mild and is more than offset by the water content of the beverage. However, plain water remains the best primary source of hydration, with caffeinated drinks ideally making up no more than 2 to 3 cups per day. Sugar-sweetened beverages like bubble tea should not be counted as healthy hydration despite their water content.

Yes, though it is uncommon. Drinking excessive amounts of plain water in a short period can lead to hyponatraemia, a condition where blood sodium levels become dangerously low. This is most often seen in endurance athletes or marathon runners who consume large volumes of plain water without electrolyte replacement. For most Singaporeans drinking in line with thirst and the formulas above, water intoxication is not a realistic risk. Symptoms include nausea, headache, confusion, and in severe cases, seizures.

PUB tap water in Singapore is safe to drink directly from the tap and is regularly tested to meet World Health Organization drinking water guidelines. It is one of the highest-quality municipal water supplies in Asia. Bottled water is not necessary for safety reasons in Singapore, is more expensive, and produces significant plastic waste. A reusable bottle filled with PUB tap water is the most practical, sustainable, and affordable option for daily hydration.