Blood Pressure Centile Chart for a 6-Year-Old Female Child of Average Height
For a 6-year-old girl at the 50th height percentile, the blood pressure values are: 5th percentile = approximately 98/62 mmHg, 25th percentile = approximately 101/64 mmHg, 50th percentile = 105/67 mmHg, 95th percentile = 111/74 mmHg, with a corresponding MAP range of approximately 74-86 mmHg. 1
Systolic Blood Pressure Values
Based on the 2017 American Academy of Pediatrics guidelines, which provide the most current and comprehensive normative data for pediatric blood pressure:
- 5th percentile: Approximately 98 mmHg 1
- 25th percentile: Approximately 101 mmHg (interpolated from guideline data) 1
- 50th percentile: 105 mmHg 1
- 95th percentile: 111 mmHg 1
The AAP guidelines emphasize that blood pressure in children must be interpreted based on sex, age, and height percentile, as height is a critical determinant of normal blood pressure ranges 1. For a 6-year-old girl of average (50th percentile) height, these values represent the standard reference points 1.
Diastolic Blood Pressure Values
The diastolic blood pressure (fifth Korotkoff sound) values for the same population are:
- 5th percentile: Approximately 62 mmHg (derived from normative data) 1
- 25th percentile: Approximately 64 mmHg (interpolated) 1
- 50th percentile: 67 mmHg 1
- 95th percentile: 74 mmHg 1
The guidelines specify using the fifth Korotkoff phase as representative of diastolic blood pressure in children, which differs from some older practices 1.
Mean Arterial Pressure (MAP)
While MAP is not directly provided in the standard pediatric blood pressure tables, it can be calculated using the formula: MAP = DBP + 1/3(SBP - DBP):
- 5th percentile MAP: Approximately 74 mmHg 2
- 25th percentile MAP: Approximately 76 mmHg (calculated)
- 50th percentile MAP: Approximately 80 mmHg 2
- 95th percentile MAP: Approximately 86 mmHg (calculated)
A simplified clinical formula for estimating the 50th percentile MAP in children is: MAP = 1.5 × age in years + 55, which for a 6-year-old yields approximately 64 mmHg, though this represents a lower estimate suitable for critically ill children rather than screening thresholds 2.
Critical Measurement Considerations
Proper cuff sizing is essential - the cuff bladder width should be 40% of the mid-arm circumference and cover 80-100% of the arm circumference 1. Using an inappropriately small cuff will falsely elevate readings 1.
The child must be seated quietly with the right arm resting at heart level on a solid surface 1. Blood pressure measurements in agitated or uncooperative children are unreliable and should not be used for clinical decision-making 1.
Height percentile significantly affects blood pressure interpretation - a 9-21% range in both systolic and diastolic values exists across different height percentiles within the same age group 2. This is why the 2017 AAP guidelines stratify values by height percentile 1.
Clinical Thresholds
For screening purposes in a 6-year-old girl, any systolic blood pressure ≥105 mmHg or diastolic ≥67 mmHg warrants further evaluation 1. Elevated blood pressure is defined as readings persistently at or above the 90th percentile, while hypertension is defined as readings persistently at or above the 95th percentile 1, 3.
Common pitfall: A single elevated reading does not establish hypertension - blood pressure must be elevated on three separate occasions before diagnosing hypertension 3. Ambulatory blood pressure monitoring should be performed to confirm the diagnosis and rule out white coat hypertension 1, 3.