Daily Water Intake Calculator

Estimates how much water to drink in a day from your body weight, exercise time and the weather, and keeps a tally of the cups you drink today.

How to use

1. Choose the "Units" and enter your "Body weight", "Sex" and "Age group".
2. If you exercised, enter "Exercise or active work today" and choose the "Intensity" and "Weather".
3. Read the estimated range of water and drinks per day, the total including food, and the number of cups.
4. Each time you drink, tap a cup button under "Drunk today" to update the progress ring and the "Last 7 days" bars.

How it works

• The estimate uses 30–35 mL of total water per kg of body weight per day, with 80% of it from drinks. The exercise extra is the activity time × the maximum hourly intake in UK Ministry of Defence guidance.
• The reference table shows adult adequate intakes from Korean (2025), US (2004) and EFSA (2010) standards.
• These values are for healthy adults. If you have been told to limit fluids, for example because of kidney or heart disease, follow your care team's instructions.
• The tally is saved by date only in this browser, and a new day starts after midnight.

Questions and answers

Do I need to drink 2 liters of water a day?

It depends on the standard, your sex and your age. In the table on the page, total water for women aged 30–49 is 2,000 mL in the Korean standard and 2.7 L in the US standard, including the water in food.

How much water should I drink if I weigh 60 kg?

With no exercise, the drinking share is about 1,440–1,680 mL a day, and total water including food is 1,800–2,100 mL.

Can you drink too much water?

Yes. Drinking a lot in a short time can dilute the sodium in your blood, which can be dangerous. The guidance quoted on the page says not to exceed 1.25 L an hour; a warning appears if your last hour is higher.

Do coffee and milk count toward my water intake?

The estimate covers water and other drinks together. The Korean value for drinks includes 200 mL of milk.