Pediatric Blood Volume Calculator

Estimates the quantity of blood based on child’s age group and weight.

Refer to the text below the tool for more information about the values used to determine the infant’s, child’s or adolescent’s blood volume.


In 1962 Nadler et al. used radioisotope labelling of circulating blood to determine an equation that estimates an individual’s blood volume, based on body surface area and body mass.

This equation can be simplified to variables that state the blood volume in mL/kg for different ages and genders, with specific use in pediatric practice.


Pediatric Blood Volume = Weight in kg x Age group variable

Age group Age group variable
Neonates 85 – 90 mL/kg
Infants 75 – 80 mL/kg
Children 70 – 75 mL/kg
Male adolescents 70 mL/kg
Female adolescents 65 mL/kg

Weight
Age Group
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Steps on how to print your input & results:

1. Fill in the calculator/tool with your values and/or your answer choices and press Calculate.

2. Then you can click on the Print button to open a PDF in a separate window with the inputs and results. You can further save the PDF or print it.

Please note that once you have closed the PDF you need to click on the Calculate button before you try opening it again, otherwise the input and/or results may not appear in the pdf.


 

Pediatric Blood Volumes

In 1962 Nadler et al. used radioisotope labelling of circulating blood to determine an equation that estimates an individual’s blood volume, based on body surface area and body mass. This equation can be simplified to variables that state the blood volume in mL/kg for different ages and genders, with specific use in pediatric practice.

Pediatric Blood Volume = Weight in kg x Age group variable

Age group Age group variable
Neonates 85 – 90 mL/kg
Infants 75 – 80 mL/kg
Children 70 – 75 mL/kg
Male adolescents 70 mL/kg
Female adolescents 65 mL/kg
 

Guidelines for Safe Blood Volume Drawing

Existing guidelines regarding the drawing of blood samples from infants and children range from 1% to 5% of total blood volume (TBV) over a period of 24 hours, with no more than 10% of TBV over a period of 8 weeks.

The current studies include findings that conclude a minimal risk with one-off sampling of up to 5% of TBV.

The blood volume required and the type of laboratory test ordered will inform the choice of site and procedure:

  • Venous site – venepuncture, needs to be performed by trained phlebotomist;
  • Finger or heel-prick – capillary or skin sampling.

However, blood from capillary sampling (whilst similar to arterial sampling in oxygen content) may be contaminated by skin flora.

 

References

Nadler SB, Hidalgo JH, Bloch T. Prediction of blood volume in normal human adults. Surgery. 1962; 51(2):224-32.

John F. Butterworth IV, David C. Mackey, John D. Wasnick. Morgan and Mikhail's Clinical Anesthesiology. 5th Edition. 2013.

Howie SR. Blood sample volumes in child health research: review of safe limits. Bull World Health Organ. 2011; 89(1):46-53.


Specialty: Pediatrics

Article By: Denise Nedea

Published On: August 11, 2020

Last Checked: August 11, 2020

Next Review: August 11, 2025