Daily Water Intake Calculator

Calculate how much water you should drink each day based on your weight, activity level, sex, and climate. Optimised for UAE conditions where heat significantly increases hydration needs.

Assigned sex

Weight

Kilograms

Enter a valid weight

Activity level

Exercise is at least 15-30 minutes of elevated heart rate activity.

Exercise 3-5 days/week

Environment (optional)

You need more water in hot, humid, or dry places, or if you live at a high altitude.

Some heart, kidney, liver, and endocrine conditions require personalised fluid advice from a clinician.

Daily Hydration

Recommended water intake

—

L/day

Estimated cups per day

—

cups/day

In fluid ounces

—

oz/day

Daily water intake should usually be between half a gallon (8 cups) and a gallon (16 cups). One cup of water equals 8 fluid ounces.

Activity: — oz · Environment: — oz

Overview

Staying well hydrated

< 1.5 L/day

Under-hydrated

Consistently drinking below your needs can affect energy, concentration, and kidney function. Even mild dehydration can reduce physical and cognitive performance.

1.5–3 L/day

Well hydrated

Most adults fall in this range. Sip consistently throughout the day rather than drinking large amounts at once — your kidneys can only process about 1 litre per hour.

> 3 L/day

High needs

Athletes, people in hot climates, and those doing heavy manual work often need significantly more. Electrolyte balance matters at high intake — plain water alone may not be sufficient.

How much water do I really need?

Water needs depend on body size, activity, climate, and health status. The commonly cited '8 glasses a day' is a rough guide — your actual requirement may be higher or lower. Thirst, urine colour, and energy levels are practical indicators.

Does coffee or tea count?

Yes. Despite their mild diuretic effect, caffeinated drinks still contribute to daily fluid intake. Alcohol is the main exception — it increases fluid losses and should not be counted toward hydration.

What are signs of dehydration?

Common signs include dark urine, fatigue, dry mouth, headaches, and reduced concentration. If symptoms are severe or you have a medical condition affecting fluid balance, speak with a clinician.

Fluid needs vary widely. People with heart, kidney, or endocrine conditions should get personalised hydration advice from a clinician.