Water Intake Calculator: How Much Water Should I Drink a Day?

How the water intake calculator works

This water intake calculator shows the daily total water intake the National Academies of Sciences, Engineering, and Medicine set for healthy adults, and splits it between drinks and food. The values are adequate intakes, based on what healthy, well-hydrated people actually consume.

Men average about 3.7 liters (125 fl oz) of total water a day and women about 2.7 liters (91 fl oz). About 80% typically comes from water and other drinks and about 20% from food. That puts the drink portion at roughly 100 fl oz (about 12 cups) for men and 73 fl oz (about 9 cups) for women.

Total water includes all beverages. Coffee, tea and milk count too, and so does water-rich food like fruit, vegetables and soups. People who are very active or live in hot climates may need more than the baseline, which is why the calculator flags those days.

An easy check through the day is thirst and pale-yellow urine. Building water into routines, like a glass when you wake up, one with each meal and one around training, makes the target easy to hit without counting every sip.