How to Use the Water Reminder Interval Calculator
Deciding to drink more water is easy — figuring out exactly when and how much throughout the day is the hard part. Enter your wake-up time, bedtime, daily water goal, and the size of a typical glass, and this calculator tells you how many glasses you need and how often to schedule a reminder to hit your goal.
The math is simple: your waking hours are split evenly across the number of glasses needed to reach your goal. For example, if you're awake 16 hours and need 10 glasses at 8 oz each, you'd want a reminder roughly every 1 hour 36 minutes.
Once you have your interval, set it as a recurring alarm or in a hydration app so you don't have to think about the schedule yourself. On hot days or after intense exercise, bump up your goal and recalculate for a shorter interval.
Frequently Asked Questions
A common guideline is about half an ounce to an ounce per pound of body weight, which works out to roughly 64-100 oz (about 2-3 liters) for most adults. Adjust for activity level and climate.
Caffeinated drinks have a mild diuretic effect, so they don't count fully toward pure hydration. It's best to meet most of your goal with plain water.