Personalised water intake based on your body & lifestyle
Hydration tips
Drink 500 ml of water first thing in the morning, before coffee or food. Your body is mildly dehydrated after 7–8 hours of sleep.
Set a phone reminder every 1–2 hours. Aim for one medium glass (250 ml) at each prompt. Consistent sipping beats occasional gulping.
Around 20% of daily water intake comes from food. Cucumbers, watermelon, strawberries, and lettuce are over 90% water by weight.
Drink 500 ml 2 hours before exercise, sip 150–250 ml every 15–20 minutes during, and rehydrate with at least 500 ml afterward.
Moderate coffee (2–3 cups/day) has minimal diuretic effect and contributes to fluid intake. Alcohol, however, is genuinely dehydrating.
Keeping a large, marked bottle on your desk makes drinking a visual habit. Aim to refill a 1 L bottle 2–3 times through the day.
Know the signs
Frequently asked
Not exactly. The 8×8 rule (eight 240 ml glasses = ~1.9 L) is a rough baseline that works for many sedentary adults in temperate climates. But actual needs vary significantly with body weight, activity level, diet, and environment. This calculator gives you a more personalised estimate based on the latest evidence-based formulas.
Yes — all beverages contribute to total fluid intake, including herbal teas, milk, juices, and sparkling water. Even caffeinated drinks like coffee and black tea count, although high caffeine intake can have a mild diuretic effect at large quantities. Alcohol is the main exception, as it actively increases fluid loss.
Yes — drinking an excessive amount in a short time can cause hyponatraemia (low sodium), also called water intoxication. This is rare in healthy adults but can occur during endurance events. If you're doing prolonged intense exercise, also replace electrolytes — not just water.
Pregnant women need around 300–500 ml extra per day to support increased blood volume and amniotic fluid. Breastfeeding mothers need even more — typically an additional 700 ml/day — as milk production draws on body fluids. Both are included in the calculator's additional factors.
Absolutely. In hot and humid environments you can lose 1–2 L of water per hour through sweat. Even sitting in air conditioning in a hot country increases insensible fluid losses through breathing and skin evaporation. Altitude also matters — higher elevation increases respiratory water loss and urine output.