Ounces, cups and glasses of water a day
Most advice on water is in millilitres, most bottles and cups are in ounces. Here is the same daily amount in both, worked out from your weight rather than a one-size number.
How many ounces of water a day
Drip works out the amount from weight: 35 ml per kilogram for men and 31 ml for women, a little more if you are taller than 170 cm, and 500 ml more on a workout day.
In ounces per pound that is about 0.54 fl oz for men and 0.48 fl oz for women. A man who weighs 176 lb needs about 96 fl oz a day; a woman who weighs 121 lb needs about 57 fl oz.
Examples
Worked out by Drip’s formula, without a workout:
- man, 5′11″, 176 lb: 2,850 ml, about 96 fl oz or 12 cups
- man, 5′9″, 154 lb: 2,450 ml, about 83 fl oz or 10 cups
- woman, 5′5″, 154 lb: 2,150 ml, about 73 fl oz or 9 cups
- woman, 5′5″, 132 lb: 1,850 ml, about 63 fl oz or 8 cups
- woman, 5′5″, 121 lb: 1,700 ml, about 57 fl oz or 7 cups
How many cups and glasses
A US cup is 8 fl oz, about 237 ml; Drip counts a glass as 250 ml. To get cups, divide your ounces by 8. To get glasses, divide your millilitres by 250.
Drip’s calculator never goes below 1,500 ml or above 4,500 ml a day. That is about 51 to 152 fl oz, or 6 to 19 cups.
Bottles and gallons
A standard 16.9 fl oz bottle holds 500 ml, so most adults need three to seven of them a day. A gallon is 128 fl oz, about 3,800 ml: more than Drip’s formula gives most people.
Questions
How many ounces of water should I drink a day?
About 0.54 fl oz per pound of body weight for men and 0.48 fl oz for women by Drip’s formula, adjusted for height, plus about 17 fl oz on a workout day.
How many glasses of water a day?
Divide your amount in millilitres by 250. For a man who is 5′11″ and 176 lb that is 11 glasses, for a woman who is 5′5″ and 121 lb it is 7.
Should I drink a gallon of water a day?
Usually not. A gallon is about 3,800 ml, more than Drip’s formula gives most people. If you want to drink far more than usual, talk to a doctor.
This is not medical advice. If you have kidney or heart problems, are pregnant or your doctor limits fluids, your doctor sets the amount.