This gives a simple starting estimate for daily water intake based on body weight, with an adjustment for exercise. Individual needs vary with climate, health conditions, and diet, so treat this as a baseline rather than a strict rule.
Water Intake Calculator
LiveThe formula
A 170 lb person with no additional exercise: 170 × 0.5 = 85 oz (about 2.51 liters, or 10.6 cups) per day.
Step-by-step guide
- Enter your body weight.
- Enter your typical daily exercise minutes, if any, to add a hydration allowance.
- Read your daily water target in ounces, liters, and cups.
Common mistakes
Frequently asked questions
Is "8 glasses a day" the same as this estimate?
Roughly, for an average-sized adult — 8 cups is about 64 oz, close to but not identical to the weight-based estimate here. Individual needs vary more than a single flat number suggests, which is why this calculator scales with body weight.
Can I drink too much water?
Yes, in rare cases drinking extreme amounts of water in a short time can be harmful. This calculator gives a reasonable daily target, not a reason to force-drink large amounts quickly.
Do certain health conditions change this?
Yes — some medical conditions require more or less fluid than a general formula suggests. If you have a relevant health condition, follow your doctor's specific guidance over this general estimate.
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