Water intake at 90 lb
How much water is enough? Use the form for your own numbers, or read the example for 90 lb with 30 minutes of exercise.
How it works
Take your weight in kilograms and multiply by 35. Then add 350 for each half hour of exercise. That is your daily water target in milliliters. On this page 90 lb with 30 minutes of exercise gives a weight term of 40.82 × 35 = 1428.7 ml.
Worked example
For 90 lb with 30 minutes of exercise, the weight is 40.82 kg. Body weight gives 40.82 × 35 = 1428.7 ml. Exercise adds 350 × 30 divided by 30 = 350 ml. The daily target is 1778.7 ml. Divide by 1000 for 1.78 liters. Divide by 29.5735 for 60.1 ounces. Divide by 8 for 7.5 cups.
Common questions
Can I drink too much water?
Yes, though it is uncommon. Drinking far more than you need in a short time can dilute the salts in your blood. Spread your intake through the day. At 90 lb with 30 minutes of exercise, spread over 16 waking hours, 1.78 liters is about 111 ml an hour.
How many ounces or cups is that?
A US fluid ounce is 29.5735 milliliters and a cup is 8 ounces. At 90 lb with 30 minutes of exercise, 1778.7 ml is 60.1 ounces or 7.5 cups.
Do coffee and tea count toward my water?
Most drinks count toward your fluid total, though plain water is the simplest choice. At 90 lb with 30 minutes of exercise, 1.78 liters a day is about 8 cups spread across the day.
Does food count toward the total?
Food contains water. Treat the result as a goal for your total fluid across the day and not a quota for drinks alone. At 90 lb with 30 minutes of exercise, treat 1.78 liters as a goal for the day, not a quota for one sitting.
What if I exercise more or less than this?
Change the exercise minutes. Each 30 minutes adds 350 milliliters. At 30 minutes the page adds 350 ml. An extra 30 minutes would bring the total to 2128.7 ml.