Maintenance Fluids (Holliday–Segar)
Estimated isotonic maintenance rate from body weight (teaching model).
Calculator
How it works
What this tool does
Calculates Holliday–Segar maintenance: first 10 kg → 100 mL/kg/day; next 10 kg → +50 mL/kg/day; each kg beyond 20 → +20 mL/kg/day. Hourly rate = daily ÷ 24 (equivalent to 4–2–1 mL/kg/hr segments).
Summary
Daily mL = if weight ≤10: 100 × weight if weight ≤20: 1000 + 50×(weight−10) else: 1500 + 20×(weight−20) Hourly mL = daily / 24
Cautions
Not for neonatal-specific fluid rules, hypernatremia correction, or fluid restriction without specialist input.
Educational tool only—not for diagnosis or treatment decisions.