Maintenance IV Fluid Rate Calculator

Work out maintenance iv fluid rate instantly with clear inputs, formula shown and shareable results.

About Maintenance IV Fluid Rate Calculator

Applies the Holliday-Segar 4-2-1 rule: 4 mL/kg/h for the first 10 kg, 2 mL/kg/h for the next 10 kg and 1 mL/kg/h thereafter.

Formula

Holliday-Segar 4-2-1 rule

Rate = 4 x first 10 kg + 2 x next 10 kg + 1 x remaining kg, in mL/h

Worked example

With the default values below, Maintenance IV Fluid Rate Calculator returns Maintenance rate of 64.0. Change any input above and every figure here is recalculated in your browser.

Inputs used

Body weightaccepts 0.5–150 kg: 24 kg
Additional allowance for fever or lossesaccepts 0–50 %: 0 %

Results

Maintenance rate: 64.0 mL/h
Volume over 24 hours: 1,536 mL
Rate before the extra allowance: 64.0 mL/h

Step by step

1Values used
2Holliday-Segar 4-2-1 rule
3Maintenance rate= 64.0 mL/h
4Volume over 24 hours= 1,536 mL
5Rate before the extra allowance= 64.0 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

Does this apply to adults?

The rule scales to adults but many units cap maintenance fluids and prefer 25 to 30 mL/kg/day for adults.

Should deficits be added?

Yes. Existing dehydration and ongoing losses are replaced in addition to maintenance.