How this estimate works
BonusBurn multiplies body weight by 35 millilitres per kilogram and rounds to the nearest 50 ml. This is a simple heuristic, not an EFSA recommendation. EFSA instead gives adequate total-water references of 2.0 litres for adult women and 2.5 litres for adult men, including water from drinks and food. Weather, exercise, illness, pregnancy and medical conditions can change needs substantially.