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Water Intake Calculator

How much water to drink a dayRuns locally · nothing uploaded

Suggested daily water
2.5 L
Per waking hour
156 ml
💧💧💧💧💧💧💧💧💧💧about 10 cups (250 ml each)

Estimated as body weight × 30–35 ml plus about 350 ml per 30 minutes of exercise. Food also provides water. People with kidney or heart conditions should follow medical advice.

Estimates based on general formulas, for information only. Not a substitute for professional medical advice, diagnosis or treatment.

Also works as:daily water intakehow much water to drinkhydration calculator

How it works

When to use it

  • Estimate how much water to drink per day.
  • Account for exercise and hot weather.

Formula

Base = body weight (kg) × 33 ml

A common rule of thumb is 30–35 ml per kg.

Exercise = minutes ÷ 30 × 350 ml
Climate: hot / sweating +500 ml; cold and dry +200 ml

Worked example

Given: 65 kg (143 lb), 30 minutes of exercise, mild climate

  1. Base = 65 × 33 = 2,145 ml.
  2. Exercise = 30 ÷ 30 × 350 = 350 ml.

Result: About 2,495 ml (≈ 84 fl oz) a day.

Reading the result

  • This is total water; food supplies part of it.
  • Pale yellow urine is a practical sign you're drinking enough.

Limitations

  • Exercise and climate additions are rules of thumb; long, sweaty sessions also need electrolytes.
  • If you have kidney, heart or liver disease, follow your doctor's fluid limits.

Sources

  • National Academies: Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate (2005)

How to use

  1. 1Enter your weight.
  2. 2Add exercise time and climate.
  3. 3Read your daily water target.

FAQ

Do I need 8 glasses a day?

Not necessarily; needs vary with size, activity and heat, and food provides water too.

Can I drink too much?

Drinking a lot very quickly can cause low sodium; spread it through the day.

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