Daily Water Intake Calculator — How Much Should You Drink?
"8 glasses a day" is a myth that ignores your body size, activity and climate. Your real hydration need scales with your weight and rises with exercise and heat — highly relevant if you live in the Gulf, South Asia or anywhere hot. Enter your details for a personalised daily water target.
A guideline for healthy adults. Some conditions require fluid limits — follow your doctor's advice if so.
General wellness guidance only — not medical advice. People with kidney, heart or other conditions should follow their doctor's fluid recommendations.
How to use this tool
- Enter your weight — hydration needs scale with body size.
- Pick your typical daily exercise and your climate (hot climates raise the target notably).
- Press Calculate for litres, cups and bottles per day.
Frequently asked questions
Is 8 glasses a day actually correct?
It's a rough average, not a personal target. Needs scale with weight, activity and heat — a 90 kg person training in Dubai needs far more than a 50 kg person in a cool office. This tool personalises it instead of using one-size-fits-all.
Do tea, coffee and food count toward hydration?
Yes. Food provides roughly 20% of fluid intake, and moderate tea/coffee counts despite mild diuretic effects. The target here is total fluid; if you eat lots of water-rich foods, you may comfortably drink a little less.
How do I know if I'm drinking enough?
The simplest sign is urine colour — pale straw means well hydrated; dark yellow means drink more. Thirst, headaches and fatigue are later signals. In hot climates, don't wait for thirst.
Can you drink too much water?
Rarely, but yes — excessive intake in a short time can dilute blood sodium (hyponatraemia), which is dangerous. Spread intake through the day rather than forcing litres at once, and don't wildly exceed your target.
Does this apply in Ramadan or fasting?
During fasting, focus on hydrating well between the fast's end and start — aim for your daily target across those hours, favouring water over sugary drinks, and go easy on caffeine which increases fluid loss.