How Much Water to Drink Based on Body Weight (mL per kg)
A common range is 30-35 mL of water per kg of body weight per day. A 70 kg adult falls in a range of about 2100-2450 mL/day from fluids (general guidance, not medical advice).
Open the interactive Everyday Lifestyle tool →Formula: mL/day = weight (kg) x 30 to 35
Key facts
| Formula | mL/day = weight (kg) x 30 to 35 |
|---|---|
| 70 kg, low end (x30) | 2100 mL/day |
| 70 kg, high end (x35) | 2450 mL/day |
| Range used | 30-35 mL/kg/day |
Frequently asked questions
How much water should a 70 kg person drink?
Roughly 2100-2450 mL/day using 30-35 mL per kg (70 x 30 = 2100, 70 x 35 = 2450).
Why is there a range instead of one number?
Needs shift with activity level, climate, and diet, so 30-35 mL/kg is a starting range rather than a fixed target.
Does this include water from food?
No, this range is for fluids specifically; food typically contributes additional water on top of this.
Related pages
The calculations on this page are estimates based on common general-purpose formulas. They are not medical advice -- consult a doctor or other qualified professional for decisions about your health.
Water Intake per Kilogram Calculator is part of Everyday Lifestyle on GOAT Lab — a free reference you can use without signing up, and it works offline. Open the tool above for any custom value.
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