Water Intake Calculator

Find your personalized daily water target based on your body weight, activity level and climate.

Enter your details and hit calculate — your daily water target shows up here.
Your daily water target
0 liters

Fluid ounces

8oz glasses

This is a general estimate, not medical advice. Needs vary by individual health, medications and climate — talk to a doctor for a personalized target if you have a health condition.

How this calculator works

This tool estimates daily water needs using a common baseline of roughly half an ounce to one ounce of water per pound of body weight, adjusted upward for higher activity levels and hot or humid climates where fluid loss through sweat increases.

Frequently asked questions

Does coffee or tea count toward this total?

Moderate caffeine intake contributes to hydration too, despite the old myth that it's dehydrating — but plain water is still the most reliable way to hit your target.

What if I have a kidney or heart condition?

Talk to your doctor before using general hydration targets — some medical conditions require restricted or increased fluid intake, and this calculator isn't a substitute for medical guidance.