Pediatric Maintenance Fluids (Holliday-Segar)
Hourly maintenance IV fluid rate by weight using the 4-2-1 rule.
Understanding this tool
Why nurses use it
The Holliday-Segar 4-2-1 rule estimates hourly maintenance IV fluids for children by weight — a foundation taught in paediatric nursing and used when prescribing maintenance fluids.
When to use it
Use for maintenance fluid rate estimation in stable paediatric patients — not for bolus resuscitation, large adolescents, obesity, or complex dehydration without prescriber orders.
Calculate
How to use this calculator
- Enter weight in kg.
- Note hourly and daily maintenance rates.
- Adjust for fever, losses, NPO status, and electrolyte monitoring per orders.
How the calculation works
4 mL/kg/hr for first 10 kg + 2 mL/kg/hr for next 10 kg + 1 mL/kg/hr for each kg above 20. For larger adolescents or complex cases, use local pediatric protocol.
Formula used by this tool — verify units before applying at the bedside.
Worked example
Limitations & clinical notes
- Does not replace isotonic bolus therapy for shock/dehydration.
- Neonates and complex fluid needs require specialist protocols.
- For larger adolescents, obesity, renal/cardiac disease, or perioperative/complex cases, use local pediatric protocol and prescriber orders — do not apply 4-2-1 automatically.
References
Key sources: Holliday MA, Segar WE — maintenance fluids.
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Disclaimer: This calculator is for educational and bedside double-check purposes only. It does not replace institutional protocols, prescriber orders, pharmacist verification, or clinical judgment. Always follow your local policies — especially for high-risk medications, infusions, pediatrics, and critical care. If the patient is acutely unwell, escalate immediately rather than relying on any calculator output.