Maintenance Fluids (Holliday-Segar) Calculator

Maintenance Fluids (Holliday-Segar) Calculator for Pediatrics. The arithmetic is a baseline rather than a completed fluid prescription. Clinical illness, fluid balance and laboratory monitoring determine whether a different volume is appropriate. No automatic obesity correction, additional loss replacement, fluid restriction or universal daily cap is applied.

For shared guidance on choosing a tool and documenting results, read the clinical calculator workflow.

How this calculator works

Holliday-Segar daily maintenance arithmetic uses 100 mL/kg for the first ten kilograms, 50 mL/kg for the next ten, and 20 mL/kg above twenty. The calculator displays the daily total divided by 24 and, separately, the hourly 4-2-1 approximation. Weight can be entered in kg or lb.

When to use this calculator

Use this baseline calculation for a child older than 28 days and younger than 16 years when a clinician considers it appropriate. The age scope follows the cited NICE pediatric guidance. Maintenance is distinct from resuscitation, correction of a deficit and replacement of ongoing losses.

Inputs used

  • Child older than 28 days and younger than 16 years?
  • Clinically appropriate dosing weight (kg)

Clinical interpretation

The arithmetic is a baseline rather than a completed fluid prescription. Clinical illness, fluid balance and laboratory monitoring determine whether a different volume is appropriate. No automatic obesity correction, additional loss replacement, fluid restriction or universal daily cap is applied.

Worked example

For 26 kg, the daily estimate is 1000 + 500 + 120 = 1620 mL/day. Dividing by 24 gives 67.5 mL/hour. The separate 4-2-1 calculation gives 40 + 20 + 6 = 66 mL/hour; it is not mathematically identical to the daily formula.

Limitations and safety notes

Neonates require age-specific assessment and are not included. Kidney or cardiac disease, abnormal fluid distribution and unusual body composition can make simple weight-based maintenance unsuitable. The tool does not choose fluid composition, electrolyte additives or a resuscitation bolus.

Frequently asked questions

Why do the two hourly figures differ?

One is the exact daily total divided by 24; the other is the separate 4-2-1 approximation.

Does the estimate include dehydration replacement?

No. Maintenance, existing deficits and ongoing losses are separate clinical calculations.

Can this formula be applied to a newborn?

Not in this implementation. Neonates need their own age-specific fluid assessment.

References

  • Daily100/50/20 maintenance calculation and neonatal-specific alternative; estimate distinguished from a clinical fluid prescription. https://www.nice.org.uk/guidance/ng29/chapter/recommendations

Editorial review and citation methodology

Maintained by the Quick Medical Calculator Editorial Team. Content record date: September 9, 2026. A content date is not evidence of independent clinical review. Individual clinical sign-off is not recorded on this page.

  • Prefer original validation studies for scoring systems and prediction tools.
  • Use current specialty society guidance, transplant allocation policy, public health guidance, or regulator resources when they govern clinical use.
  • Include limitations and safety notes when a calculator is population-specific, context-dependent, or unsuitable as a standalone decision tool.

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