Estimate a daily drink volume from body weight and a millilitres-per-kilogram sketch.
| Daily volume | – |
| Litres / day | – |
Use this calculator for millilitres per day = weight × ml/kg, then litres = that volume ÷ 1000. The default 30 ml/kg is a round adult figure, not a lab result. Heat, lactation, exercise, and kidney disease change the need. “Eight glasses” is marketing, not physiology.
Weight can be entered in kilograms (kg) or pounds (lb); the calculator converts to kilograms before the formula. Daily volume is shown in millilitres (ml) or fluid ounces (fl oz), and in litres (L) or gallons (gal).
Weight: Body weight, in kg or lb.
ml / kg: Millilitres per kilogram. 30 is a common adult sketch.
ml / day: Daily volume in millilitres.
Litres / day: The same volume in litres.
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