Maintenance Fluids Calculator
The maintenance fluids calculator (MIVF calculator) uses the HollidaySegar method and the 421 rule to determine the daily and hourly need for fluids in children. As well as finding out these pediatric maintenance fluids, you can also work out the proper size of the pediatric fluid bolus to be given in times of need.
We try our best here at Omni Calculator to make our calculators as precise and reliable as possible. However, this tool can never replace professional medical advice, diagnosis, or treatment. All information on this website is for informational purposes only and is not intended to and should not serve as a substitute for medical consultation. Always seek the advice of a health provider. Before administering any drug, fluid, blood, or treatment to your kid patient, make sure you know the correct dose and method.
How to use pediatric maintenance fluids calculator?

Determine if you should use the maintenance fluids calculator, as the formula used here has its limitations. You should not use it for newborns under 14 days old, as it overestimates the fluids needed. Also, the formula is not suitable for children under 3 kilograms. The calculator will warn you about that.

Input the child's weight. Consider using the ideal body weight and the ideal weight calculator in obese patients.

You will get three results. The first is daily maintenance fluids — the fluid needed for the whole day — to be given within 24 hours.

In the next line, you'll see the Fluids flow rate. It tells you how fast the intravenous infusion should be.

The last line informs you about the pediatric fluid bolus amount. Check the section below to find out more.
HollidaySegar method and 421 rule
The formula used in our MIVF calculator is an old, wellestablished method, called after its developers, pediatricians
.The assumption that allows this formula to work is that a fixed amount of fluid is needed for every kilogram per day. The modification of this principle, called 421 rule, gives you a similar answer, but per hour. See the summary of both rules below.
Weight  HollidaySegars rule  421 rule 

First 10 kg (310 kg)  100 ml/kg/24h  4 ml/kg/h 
Next 10 kg (1120 kg)  50 ml/kg/24h  2 ml/kg/h 
Above 20 kg  20 ml/kg/24h  1 ml/kg/h 
Are you using imperial units? Don't worry! The maintenance fluids calculator can easily convert between any unit with its builtin weight converter.
Please note that in obese patients, you should think about using the ideal body weight. The best way to monitor a child's weight and weighttoheight ratio is to check how they behave in percentile ranges. Try our BMI percentile calculator, weight percentile calculator, and take a look at the height percentile calculator for any height concerns.
How to use MIVF calculator — practical example
Let's have an example to keep everything clear. How much fluid would a child of 14 kg need?

For 24 hours — HollidaySegar method
first 10 kg × 100 ml/kg/24h + next 4 kg × 50 ml/kg/24h = 1200 ml/24h

For one hour — 421 rule
first 10 kg × 4 ml/kg/24h + next 4 kg × 2 ml/kg/24h = 48 ml/24h
The answer: the amount of daily pediatric maintenance fluids is 1200 ml, and the hourly demand is 48 ml.
Pediatric fluid bolus
The term 'bolus' means an intravenous dose of a drug given relatively quickly and very often directly from hand. A bolus is often used in acute states when there is a need for the drug to reach the desired place (e.g., heart in case of resuscitation) and act as fast as possible.
A fluid bolus is given to fill the vascular bed quickly and is given mostly in the presence of hypovolemic shock.
In children, the amount of fluid given in bolus can be calculated using the formula:
bolus fluids = weight (kg) × 20 ml
with the maximum limit of 1000 milliliters = 1 liter.
This amount should be given as fast as possible — as shock is a direct lifethreatening state.
FAQ
How do I calculate maintenance fluids for children?
To calculate the volume of fluid to be administered according to the 421 rule, which provides hourly fluid requirements, you can use the following guidelines:

For the first 10 kilograms (310 kg) — 4 ml/kg/h.

For the next 10 kilograms (1120 kg) — 2 ml/kg/h.

For weights above 20 kilograms — 1 ml/kg/h.
What is MIVF?
MIVF (maintenance intravenous fluids) refers to the continual delivery of fluids through an intravenous (IV) line to maintain a patient's optimal hydration and electrolyte balance.
This medical intervention is used when patients cannot meet their fluid requirements through oral intake alone, often due to various medical conditions, surgeries, or other healthrelated challenges.
Why is D5NS included in pediatric maintenance fluid regimens?
D5NS (5% dextrose in normal saline) is included in pediatric maintenance fluid regimens to provide a controlled glucose supply, meeting high energy demands. It helps maintain fluid and electrolyte balance, and its versatility addresses diverse clinical needs, making it a valuable choice in pediatric care.
What is the recommended maintenance fluid volume for a 13 kg pediatric patient?
The recommended maintenance fluid volume for a 13 kg (28.7 lb) pediatric patient is as follows:
 Daily maintenance fluids: 1,150 ml/24h;
 Fluids flow rate: 46 ml/hour;
 Fluid bolus: 260 ml.