Water Intake Calculator
Find your daily hydration target based on your body and lifestyle. Dehydration is a hidden sleep disruptor — staying hydrated helps you sleep deeper.
Hydration & sleep
Most people don't realize how strongly hydration affects sleep quality. Both too little and too much water at the wrong time disrupts your night.
Even mild dehydration raises cortisol, dries nasal passages (worsening snoring), and causes cramps — all fragmenting sleep and reducing deep sleep.
Stop heavy drinking 1–2 hours before sleep. Too much water at night means waking up to urinate, breaking your sleep cycles.
Fruits, vegetables and soups contribute ~20% of daily water needs. The calculator gives you the amount you need to actually drink.
Pale straw yellow = well-hydrated. Dark yellow = drink more. The most reliable daily hydration indicator.
Common questions
Daily water intake by weight, activity, and climate
This page is built for common hydration searches: “how much water should I drink by weight,” “water intake calculator kg,” “water intake calculator pounds,” and “does dehydration affect sleep.”
A practical baseline is about 30-35 ml per kg of body weight, then adjusted upward for exercise, hot weather, and heavy sweating.
Training days increase fluid needs. If sweat loss is high, add water earlier in the day instead of trying to catch up right before bed.
Warm and humid environments increase fluid loss. The calculator raises the estimate when climate makes dehydration more likely.
Good hydration can reduce dry mouth, cramps, and nighttime discomfort. Taper large drinks 1-2 hours before bed to avoid waking to pee.