How much water should I drink a day?

The old rule of thumb regarding water intake was 8 glasses of water a day. The true rule to follow regarding how much water you need to drink for your body to stay hydrated, take your body weight and divid it in half and that is how many ounce of water you need to drink a day.

Example: my weight is 170 lbs /2= 85 ounce of water a day
To help you with the My Fitness Pal app... When you are entering how much water you have drank in a day there are 8 ounces in a cup.