Water Intake Calculator — Daily Water Goal
What is Water Intake Calculator — Daily Water Goal
The water intake calculator estimates how much water you should drink per day based on your body weight, activity level, and climate. The baseline is 33 ml of water per kilogram of body weight, plus 350 ml if you are moderately active (30 to 60 minutes a day) or 700 ml at high activity, plus 500 ml in a hot or humid climate. This is a general guideline based on weight, not medical advice. Needs change with health conditions, medication, and pregnancy, and food and other drinks also count toward your intake.
How to use
- Select Metric (kg) or Imperial (lbs) using the toggle.
- Enter your weight in the weight field.
- Pick your activity level: low, moderate (30 to 60 minutes a day), or high.
- Pick your climate: temperate or hot and humid.
- Read your daily water goal in litres, with ml, cups, and fluid ounces below.
When to use it
Want a concrete water goal to aim for? Enter 70 kg with moderate daily activity in a temperate climate and you get about 2.66 L per day (2660 ml, roughly 11 cups). Drop the activity to low and the same person lands at about 2.31 L (2310 ml). Fill your bottle to match the number and keep track through the day.
Frequently asked questions
How much water should I drink a day?
A common rule of thumb is around 33 ml per kilogram of body weight, with extra added for exercise and hot climates. A 70 kg person with moderate activity in a temperate climate lands at about 2.66 L a day. The calculator works out your own figure.
Does coffee or tea count toward my intake?
Yes. Coffee and tea contribute to your total fluid intake despite containing caffeine. Food also counts, especially fruit and vegetables, which supply part of the fluid you take in through the day.
How much water for a 70 kg person?
With moderate activity in a temperate climate it comes to about 2.66 L per day (2660 ml). At low activity it drops to about 2.31 L (2310 ml). Hot or humid weather adds roughly 500 ml on top.
Do I need more water when it's hot or when I exercise?
Yes. Exercise and heat increase fluid loss through sweat. The calculator adds 350 ml for moderate activity or 700 ml for high activity, plus another 500 ml in a hot or humid climate.
Can I share this tool with my inputs pre-filled?
Yes. The URL updates automatically as you type. Copy it from the address bar or use the Share button, and anyone who opens the link will see your exact inputs ready to go.
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