Paediatric Fluid Requirement Calculator

Work out paediatric fluid requirement instantly with clear inputs, formula shown and shareable results.

About Paediatric Fluid Requirement Calculator

Applies the Holliday-Segar daily rule — 100 mL/kg for the first 10 kg, 50 for the next 10 and 20 thereafter — and adds any dehydration deficit.

Formula

Holliday-Segar daily maintenance

100 mL/kg for the first 10 kg + 50 mL/kg for the next 10 kg + 20 mL/kg beyond 20 kg; deficit (mL) = weight (kg) x 1000 x dehydration fraction

Worked example

With the default values below, Paediatric Fluid Requirement Calculator returns Total fluid over 24 hours of 1,400. Change any input above and every figure here is recalculated in your browser.

Inputs used

Body weightaccepts 1–80 kg: 18 kg
Existing dehydration to replaceaccepts 0–15 %: 0 %

Results

Total fluid over 24 hours: 1,400 mL
Maintenance requirement: 1,400 mL/day
Deficit to replace: 0 mL
Maintenance rate: 58.3 mL/h

Step by step

1Values used
2Holliday-Segar daily maintenance
3Total fluid over 24 hours= 1,400 mL
4Maintenance requirement= 1,400 mL/day
5Deficit to replace= 0 mL
6Maintenance rate= 58.3 mL/h

Assumptions and limits

The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 1 decimal place, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.
This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.

Frequently Asked Questions

Should deficit be replaced quickly?

Usually over 24 to 48 hours alongside maintenance, except in shock where boluses are given first.

Which fluid should be used?

Isotonic solutions are now standard for maintenance in children to avoid hyponatraemia.