Holliday-Segar Maintenance Fluid Calculator
Use this Holliday-Segar maintenance fluid calculator (also written Holliday Segar) to estimate pediatric maintenance volume in mL/day and mL/hour from weight.
Total Daily Volume: mL/day
Per Hour Rate: mL/hour
Suggested Fluid:
Educational reference only. Confirm fluid choice and rate with local protocol and clinical judgment.
Holliday Segar Worked Example
For a 15 kg child, the daily estimate is 1,000 mL for the first 10 kg plus 250 mL for the next 5 kg, giving 1,250 mL/day. Dividing by 24 gives approximately 52.1 mL/hour. Reassess the prescription for the child's clinical condition, enteral intake, deficits, and ongoing losses.
Holliday-Segar Formula by Weight
The daily maintenance estimate is 100 mL/kg for the first 10 kg, 50 mL/kg for the next 10 kg, and 20 mL/kg for each kilogram above 20 kg. This estimates routine maintenance volume, not dehydration replacement, resuscitation, or ongoing abnormal losses.
- Holliday MA, Segar WE. The Maintenance Need for Water in Parenteral Fluid Therapy. Pediatrics. 1957;19:823-832. Original description of the weight-based pediatric maintenance fluid method.
- NICE NG29: Intravenous fluid therapy in children and young people in hospital Current guidance on assessment, prescribing, monitoring, and adjustment of IV fluids.
Frequently Asked Questions
What is the Holliday-Segar formula?
It estimates daily pediatric maintenance water as 100 mL/kg for the first 10 kg, 50 mL/kg for the second 10 kg, and 20 mL/kg for weight above 20 kg.
How do I convert daily maintenance fluid to an hourly rate?
Divide the estimated 24-hour maintenance volume by 24. This calculator reports both mL/day and mL/hour.
Does this calculator include dehydration or fluid boluses?
No. Holliday-Segar estimates routine maintenance only. Deficits, resuscitation boluses, ongoing losses, and fluid composition require separate clinical assessment.