Pediatric Fluid Requirement

About this calculator

The Holliday-Segar method, published in 1957 and still the standard bedside formula in pediatrics, estimates daily maintenance fluid needs from body weight alone: 100 mL/kg for the first 10 kg, 50 mL/kg for the next 10 kg, and 20 mL/kg for every kilogram above 20 kg. A 24 kg child, for example, needs 1,000 mL + 500 mL + 80 mL = 1,580 mL per day.

Nurses and pediatricians use this to set IV drip rates for hospitalized children who cannot drink enough on their own, converting the daily total to an hourly rate (divide by 24) — often shortened to the “4-2-1 rule” (4 mL/kg/hr for the first 10 kg, 2 mL/kg/hr for the next 10 kg, 1 mL/kg/hr above that), which is the hourly equivalent of the same formula.

This calculator takes a child’s weight and returns both the daily and hourly maintenance fluid requirement.