Mid-parental height (MPH) is a formula devised to estimate the potential adult height of a child based on the heights of the child’s parents.
How to estimate a child’s height using the mid-parental height formula:
You could try using the formula given below or use our mid parental height, MPH calculator. Our calculator also provides projected height ranges, saving you the time of working out multiple equations. Try the MPH calculator, here.
Father and Mother’s height is in inches:
For boys: MPH = (Mother’s height + Father’s height + 5 inches) ÷ 2
For girls: MPH = (Mother’s height + Father’s height – 5 inches) ÷ 2
Example: If a mother is 65 inches (5 feet 5 inches) tall and a father is 72.8 inches (about 6 feet 1 inch) tall, the estimated mid-parental height is calculated as below:
For boys: MPH = (65 + 72.8 + 5) ÷ 2 = 71.4 inches or approximately 5 feet 11.4 inches
For girls: MPH = (65 + 72.8 − 5) ÷ 2 = 66.4 inches or approximately 5 feet 6.4 inches
Father and Mother’s height is in cm:
For boys: MPH = (Mother’s height + Father’s height + 13cm) ÷ 2
For girls: MPH = (Mother’s height + Father’s height − 13cm) ÷ 2
Example: If a mother is 165 cm tall and a father is 185 cm tall, the estimated mid-parental height is calculated as below:
For boys: MPH = (165 + 185 + 13) ÷ 2 = 181.5cm
For girls: MPH = (165 + 185 − 13) ÷ 2 = 168.5cm
Errors
When examining most equations related to height and weight, it’s important to recognize that they are based on statistical data. To account for this, it can be beneficial to consider a range rather than a precise figure. The margin of error for the mid-parental method is approximately plus or minus 10 cm or plus or minus 4 inches.
It’s also important to mention that 6% of children will fall outside this range, either surpassing or falling short of the expected error rate.
The revised MPH range formula (with error allowances):
Lower range boys: MPH = ((Mother’s height + Father’s height + 5 inches) ÷ 2) – 4 cm
Upper range boys: MPH = ((Mother’s height + Father’s height + 5 inches) ÷ 2) + 4 inches
Lower range girls: MPH = ((Mother’s height + Father’s height – 13cm) ÷ 2) – 10 cm
Upper range girls: MPH = ((Mother’s height + Father’s height -13cm) ÷ 2) + 10cm
Final Thoughts
The mid parental height formula is a useful tool for estimating a child’s future height and to help chart expected growth rates. However there are many different factors which can influence a child’s adult height, including nutrition, health, sleep patterns, and illness.
References
- Braziuniene I, Wilson TA, Lane AH. Accuracy of self-reported height measurements in parents and its effect on mid-parental target height calculation. BMC Endocr Disord. 2007 Apr 2;7:2. doi: 10.1186/1472-6823-7-2. PMID: 17407570; PMCID: PMC1852563.
- Tanner JM, Goldstein H, Whitehouse RH. Standards for children’s height at ages 2-9 years allowing for heights of parents. Arch Dis Child. 1970 Dec;45(244):755-62. doi: 10.1136/adc.45.244.755. PMID: 5491878; PMCID: PMC1647404.