Pediatric Maintenance Fluid Calculator

About this calculator

The Holliday-Segar method, published in 1957 and still the standard bedside approach to pediatric maintenance fluids, estimates a child's baseline fluid requirement from body weight alone: 100 mL/kg/day for the first 10 kg, 50 mL/kg/day for the next 10 kg, and 20 mL/kg/day for each kilogram above 20 kg. Dividing the daily total by 24 gives the commonly used 4-2-1 rule for hourly rate — 4 mL/kg/hr for the first 10 kg, 2 mL/kg/hr for the next 10 kg, and 1 mL/kg/hr thereafter.

This calculator takes a child's weight and returns both the hourly and daily maintenance fluid volume by that formula. Pediatric nurses and physicians reference it when setting a baseline IV maintenance rate for a hospitalized child who isn't taking adequate fluids by mouth — it's a starting estimate for normal maintenance needs, not a substitute for individualized clinical judgment that accounts for fever, dehydration, or other fluid-shifting conditions.