About this tool
Estimate daily fluid needs using a body-weight baseline plus an activity adjustment for exercise.
Formula
Total = (35 mL/kg × weight) + (355 mL × exerciseMinutes/30)
Worked example
70 kg, 30 min exercise → 35×70 + 355 = 2,805 mL ≈ 2.8 L.
Notes
These are general estimates. Actual needs vary with climate, illness, pregnancy, and individual physiology. Thirst is a reliable signal for most healthy adults.