ZovaTool

Water Intake Calculator

Daily Water
3.31 L
3313 ml
Glasses
13
× 250 ml glass
012345
3.31 L/day
In cups (240 ml)13.8 cups
In US fl oz112.0 oz
Reminder intervalevery 72 min
Sweat replacement (per 60 min)600 ml extra
Hourly schedule (waking 16 h)
Hour 1–2414 ml · ~2 glass
Hour 3–4414 ml · ~2 glass
Hour 5–6414 ml · ~2 glass
Hour 7–8414 ml · ~2 glass
Hour 9–10414 ml · ~2 glass
Hour 11–12414 ml · ~2 glass
Hour 13–14414 ml · ~2 glass
Hour 15–16414 ml · ~2 glass

How to use the Water Intake Calculator

  1. Enter weight, age, sex.
  2. Add daily exercise minutes.
  3. Pick your climate (cool, normal, hot).
  4. Set pregnancy / lactation status if applicable.
  5. Read total daily water in liters, cups and fluid ounces.
  6. Use the hourly schedule to spread intake through your waking day.
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How much water do you actually need?

The popular '8 glasses a day' rule is a rough average — actual needs scale with body size, activity, climate and life stage.

Roughly 30–40 ml per kg of body weight covers most adults. Exercise adds about 350 ml per 30 minutes. Hot climates push needs up 10–15%. Pregnancy adds ~300 ml/day, lactation adds ~700 ml/day.

Food contributes about 20% of your water. Fruits, vegetables and soups count. Caffeinated drinks count too — mild diuretic effects are offset by their water content.