Pediatric Blood Pressure Calculator

Enter a child's age and measured blood pressure to get the mean arterial pressure (MAP) and the standard PALS age-based minimum normal systolic BP, used at the bedside to screen for hypotension.

Quick Facts

MAP formula
MAP = DBP + 1/3 (SBP - DBP)
The universal mean arterial pressure equation, weighted toward diastole.
PALS minimum SBP
70 + (2 x age in years)
For children 1-10 years; 70 mmHg for infants, 60 mmHg for neonates, 90 mmHg beyond age 10.

Your Results

Calculated
Mean arterial pressure
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DBP + 1/3 (SBP - DBP)
Age-based minimum SBP
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PALS lower limit of normal
Margin vs. minimum
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Measured SBP minus threshold
Screening result
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Hypotension screen

Ready

Enter the child's age and measured blood pressure, then calculate.

About the pediatric blood pressure calculator

This tool computes two related numbers from a child's blood pressure reading: the mean arterial pressure (MAP) and the age-based minimum normal systolic blood pressure defined by Pediatric Advanced Life Support (PALS) and Advanced Pediatric Life Support (APLS) guidelines. Together they give a quick bedside screen for hypotension - not a full hypertension percentile evaluation.

The mean arterial pressure formula

MAP is the average pressure pushing blood through the arteries during one full cardiac cycle. Because diastole (relaxation) lasts roughly twice as long as systole (contraction), MAP is weighted toward the diastolic reading rather than a simple average of systolic and diastolic BP:

MAP = DBP + 1/3 x (SBP - DBP)

For example, a reading of 100/60 mmHg gives MAP = 60 + 1/3 x (100 - 60) = 60 + 13.3 = 73.3 mmHg.

The PALS minimum systolic BP by age

PALS and APLS define an approximate lower limit of normal (roughly the 5th percentile) systolic BP that clinicians use to recognize hypotension and decompensated shock in children:

  • Neonates (under 1 month): minimum SBP is about 60 mmHg.
  • Infants (1 to 12 months): minimum SBP is about 70 mmHg.
  • Children 1 to 10 years: minimum SBP = 70 + (2 x age in years).
  • Children over 10 years: minimum SBP is about 90 mmHg, the same floor used for adults.

A measured systolic BP at or above this threshold does not rule out illness, but a reading below it is a recognized warning sign for hypotension and should prompt urgent clinical evaluation.

What this calculator does not do

  • It is not a hypertension screening tool. Detecting elevated or high blood pressure in children requires percentile charts based on age, sex, and height, such as those in the 2017 AAP Clinical Practice Guideline - this calculator does not reproduce those tables.
  • It does not replace clinical judgment, repeat measurements with a properly sized cuff, or evaluation by a pediatric clinician.
  • It does not apply to premature neonates, who have their own gestational-age-specific blood pressure norms.

Important disclaimer

This tool performs standard arithmetic for education and reference. It does not diagnose, treat, or manage any medical condition. Any concern about a child's blood pressure should be evaluated by a licensed healthcare provider.

Frequently Asked Questions

What formula does this pediatric blood pressure calculator use?
It uses the standard PALS/APLS lower limit of normal (approximately the 5th percentile) systolic blood pressure by age: 60 mmHg for neonates under 1 month, 70 mmHg for infants 1 to 12 months, 70 plus 2 times age in years for children 1 to 10 years, and 90 mmHg for children over 10 years. It also computes mean arterial pressure as diastolic BP plus one third of the difference between systolic and diastolic BP.
What is mean arterial pressure (MAP) and why does it matter?
MAP is the average pressure driving blood flow through the body during one cardiac cycle, calculated as diastolic BP plus one third of the pulse pressure (systolic minus diastolic). Because diastole lasts roughly twice as long as systole, MAP is weighted toward the diastolic reading. Clinicians use MAP to judge organ and tissue perfusion, especially in critically ill children.
Does this replace a full pediatric blood pressure percentile chart?
No. Formal hypertension screening in children uses percentile charts based on age, sex, and height, such as those in the 2017 AAP Clinical Practice Guideline. This calculator instead applies the simpler, age-only PALS minimum systolic BP threshold used at the bedside to screen for hypotension, plus MAP. A clinician should use full percentile tables for hypertension evaluation.

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