Maintenance Fluid Needs

Name: Maintenance Fluid Needs calculator — MedScore
Creator: Nabil Alzein

Routine maintenance fluid volume per 24 h as in the NICE IV-fluid guidelines (CG174 adults, NG29 children and term neonates) — volume only

Patient group

Adult (16 years and over)

Child or young person (under 16, beyond the neonatal period)

Term neonate (birth to day 28)

Body weight (in obesity: ideal body weight)

Older or frail, renal impairment, cardiac failure, or malnourished and at risk of refeeding syndrome

Enter the weight (and, for a child, the sex) to calculate

About this score

When to use

Estimates the daily maintenance water volume: NICE adult ranges, and for children the Holliday–Segar weight bands of 100, 50 and 20 mL/kg/day. ⁦[1, 2]⁩

Pearls and pitfalls

NICE gives 25–30 mL/kg/day for routine adult maintenance and lower volumes for older or frail patients, renal impairment, cardiac failure or malnutrition. ⁦[2]⁩

Summarised from the numbered sources under Evidence. Check the source before relying on a statement.

Evidence

[1] Original publication

Holliday MA, Segar WE. The maintenance need for water in parenteral fluid therapy. The 100 / 50 / 20 ml/kg/day weight bands used for children.

Pediatrics, 1957

Open source

[2] Guideline

NICE CG174, Intravenous fluid therapy in over 16s in hospital (recommendations 1.4.1–1.4.3): routine maintenance 25–30 ml/kg/day of water; consider less (for example 20–25 ml/kg/day) for patients who are older or frail, have renal impairment or cardiac failure, or are malnourished and at risk of refeeding syndrome; in obesity adjust to ideal body weight (patients rarely need more than 3 litres a day). NICE NG29, Intravenous fluid therapy in children and young people in hospital (1.4.1–1.4.2): Holliday–Segar for children and young people — males rarely need more than 2,500 ml and females more than 2,000 ml in 24 h; term neonates 50–60 (day 1), 70–80 (day 2), 80–100 (day 3), 100–120 (day 4) and 120–150 ml/kg/day (days 5–28). Volume only: fluid choice, electrolytes, losses, monitoring and rate follow the guideline and local pathway.

Open source

Last reviewed: 2026-10

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MedScore is an educational and clinical decision-support tool. It does not provide a diagnosis, a treatment, or a drug-dosing recommendation, and it does not replace clinical judgement or local guidelines. Confirm every result against the original source before acting on it. The treating clinician remains responsible for all decisions.