Holliday–Segar maintenance fluids
Daily maintenance fluid requirement by body weight (100/50/20 rule)
- NICE NG29 (children)
Sources last checked: 2026-10-13
Holliday–Segar maintenance fluids
Daily maintenance fluid requirement by body weight (100/50/20 rule)
Gives a water requirement for a well child; for acutely ill children (ADH excess) NICE NG29 describes fluid restriction and recommends isotonic fluids. In adults the formula overestimates — NICE CG174 uses 25–30 mL/kg/day.
What is the Holliday–Segar maintenance fluids?
The Holliday–Segar method estimates daily maintenance water needs from body weight: 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. Holliday and Segar derived it in 1957 from energy expenditure in hospitalised children. NICE NG29 recommends it for routine maintenance IV fluid in children.
When to use it
- Calculating routine maintenance fluid for children and young people
- Perioperative fasting and maintenance planning (with the hourly 4-2-1 approximation)
- Checking whether an IV prescription is in a plausible range
When not to use it
- Term neonates in the first 4 weeks — NICE gives separate day-by-day volumes
- Resuscitation, replacement of ongoing losses or burns — these need separate calculations
- Adults, where 25–30 mL/kg/day (NICE CG174) is more appropriate
How it is calculated
100 mL/kg/day for the first 10 kg + 50 mL/kg/day for the next 10 kg + 20 mL/kg/day for each kg above 20 kg. Hourly rate = daily volume ÷ 24; the 4-2-1 rule (4 / 2 / 1 mL/kg/h) approximates this.
Clinical pearls and limitations
- Gives a water requirement for a well child; for acutely ill children (ADH excess) NICE NG29 describes fluid restriction and recommends isotonic fluids. In adults the formula overestimates — NICE CG174 uses 25–30 mL/kg/day.
- Acutely ill children often have raised ADH; NICE recommends isotonic fluids and considering restriction to 50–80 % of maintenance.
- NICE notes that males rarely need more than 2 500 mL and females more than 2 000 mL per 24 h.
- The 4-2-1 rule (mL/kg/h) slightly overestimates the daily formula divided by 24.
Frequently asked questions
What is the 4-2-1 rule?
An hourly approximation of Holliday–Segar: 4 mL/kg/h for the first 10 kg, 2 mL/kg/h for the next 10 kg and 1 mL/kg/h for each kg above 20 kg.
How much maintenance fluid does a 15 kg child need?
1 000 mL for the first 10 kg plus 5 × 50 mL = 1 250 mL per day (≈ 52 mL/h).
Is Holliday–Segar used in adults?
It is sometimes used intraoperatively, but adult maintenance guidance (NICE CG174) uses 25–30 mL/kg/day, which is lower.
Evidence and guidelines
- Primary source: Holliday MA, Segar WE. The maintenance need for water in parenteral fluid therapy. Pediatrics 1957;19(5):823-832.
- NICE NG29. Intravenous fluid therapy in children and young people in hospital (rec. 1.4.1: use Holliday–Segar; males rarely need > 2 500 mL/day, females > 2 000 mL/day).
- Oh TH. Formulas for calculating fluid maintenance requirements. Anesthesiology 1980;53(4):351 (hourly 4-2-1 approximation).
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