How to use the Water Intake Calculator
Enter your weight and select your activity level — the tool calculates your personalized daily water goal instantly. Then use the tracker panel to log every drink throughout the day. Your progress and log are saved automatically and reset at midnight.
How the goal is calculated
- Base: 35 ml per kilogram of body weight.
- Activity multiplier: sedentary ×1.0, light ×1.1, moderate ×1.2, active ×1.3, very active ×1.5.
- Hot climate: adds 500 ml to account for extra sweat loss.
Progress bar colors
- Grey: below 50% of your goal.
- Pink: 50–79%.
- Purple: 80–99%.
- Teal: goal reached (100%+).
Frequently asked questions
How much water should I drink per day?
A common formula is 35 ml per kilogram of body weight, adjusted for activity. A 70 kg person with moderate activity needs roughly 2,940 ml/day. The old "8 glasses" rule is a rough estimate that does not account for individual variation.
Does coffee or tea count toward my intake?
Yes. Caffeinated drinks still hydrate you — the water in coffee more than offsets caffeine's mild diuretic effect. Plain water is best, but tea and coffee do count.
How do I know if I am drinking enough?
Check your urine color. Pale yellow means well hydrated. Dark yellow or amber signals you need more water. Headaches and fatigue are also signs of mild dehydration.
Does the tracker reset every day?
Yes. Your log resets automatically at midnight. Your goal (calculated from weight and activity) is remembered across days so you do not need to recalculate it every morning.