Daily Water Intake

This formula gives a quick estimate of how much water an adult might need each day based on body mass. The constant 0.033 means about 33 millilitres per kilogram, which is a simple rule-of-thumb that scales fluid needs with body size because larger bodies generally lose and use more water. It is only an approximation, since heat, exercise, diet, illness, and pregnancy can all change actual needs.

Use this when you want a fast everyday estimate of daily water intake for a person, such as planning hydration targets or checking whether a general intake goal seems sensible. It is most useful for basic health and fitness calculations, not for medical prescriptions.

• Using pounds instead of kilograms for m
• Treating the result as an exact medical recommendation
• Forgetting that the value is in litres, not millilitres