Pediatric Blood Volume Calculator

Created by Małgorzata Koperska, MD
Reviewed by Bogna Szyk and Adena Benn
Based on research by
Hazinski, M.F. Nursing Care of the Critically Ill Child, 3rd Edition Elsevier (May 2012)See 1 more source
Howie SR. . Bull World Health Organ. 2011 Jan Blood sample volumes in child health research: review of safe limits Bulletin of the World Health Organization (January 2011)
Last updated: Aug 04, 2022

Our pediatric blood volume calculator uses body weight to find the total blood volume of children. The estimated blood volume in pediatrics depends on the age of the child. As such, there are separate formulas for blood volume in newborn babies, infants under three months of age, children over three months, and adolescents.

Interested? Keep reading to learn:

  • Why pediatric blood volume is useful;
  • How pediatric blood volume is estimated; and
  • The blood volume in infants.

Please note that we designed this pediatric blood volume calculator for children only. There is a separate calculator that estimates the blood volume in adults and one that finds the volume of blood plasma.

We try our best to make our Omni Calculators as precise and reliable as possible. However, this tool can never replace professional medical advice.

Why is pediatric blood volume useful?

Similar to the adult total blood volume, these values are vital in hospital perfusion care. This includes hemodynamic and pharmacologic interventions and transfusion practices.

Additionally, these values are critical in the process of blood collection for tests. For an adult patient, collecting 20 ml of blood won't have a noticeable impact on the organism, whereas the same amount of blood is about 8% of a newborn baby's total blood volume. According to the existing guidelines, the maximum volume of blood that can be drawn safely from an infant in 24 hours ranges from 1% to 5% of his total blood volume.

How is the blood volume estimated in pediatrics?

Our pediatric blood volume calculator uses the formula:

TBV = weight * age factor

The age factor equals:

  • 100 mL/kg for premature infants;
  • 85 mL/kg for babies younger than 3 months;
  • 75 mL/kg for children over the age of 3 months;
  • 70 mL/kg for male adolescents;
  • 65 mL/kg for female adolescents.

What's the blood volume in a newborn baby?

The volume of blood in a premature neonate ranges from 89 to 105 mL per kilogram of body weight, while a full-term baby has from 82 to 86 mL/kg of blood.

What's the blood volume in infants and older children?

The blood volume in infants and older children is markedly different.

  • The blood volume in infants up to three months of age is 82-86 mL/kg.
  • It is assumed that children have around 73-82 mL/kg of blood after the third month.
  • The volume of blood per kilogram of body weight decreases with age and in puberty reaches about the same values as in adults, which is 70 mL/kg for males and 65 mL/kg for females.
Małgorzata Koperska, MD
Age group
child >3 months
Blood volume
Check out 16 similar pediatric calculators 🧒
Adjusted ageAmoxicillin pediatric dosageAPGAR score… 13 more
People also viewed…

BMR - Harris-Benedict equation

Harris-Benedict calculator uses one of the three most popular BMR formulas. Knowing your BMR (basal metabolic weight) may help you make important decisions about your diet and lifestyle.

Black hole collision

The Black Hole Collision Calculator lets you see the effects of a black hole collision, as well as revealing some of the mysteries of black holes, come on in and enjoy!

Qp/Qs ratio

The Qp/Qs calculator allows you to calculate the pulmonary and systemic blood flow and determine the magnitude of a cardiac shunt.

Quarantine activity

The quarantine weight maintenance calculator is a useful tool that will help you to maintain your weight during a pandemic.
Copyright by Omni Calculator sp. z o.o.
Privacy policy & cookies
main background