# Ponderal Index Calculator

Offers an indication of a person’s weight relative to their height, as measure of body adiposity, similar to BMI.

The Ponderal Index or the Corpulence index is a measure of leanness first proposed by Rohrer in 1921. Ponderal index is considered as an improvement over BMI. The weight (or mass) is normalized with the third power of body height, rather than the second power, as is the case for the Body Mass Index (BMI).

The PI is considered to yield valid results even for extreme values. There is a formula for adults and one for infants/children.

• `Adult PI formula = Weight (kg) / Height3 (m)`
• `Infant/Child PI formula = 100 x Weight (grams) / Height3 (cm)`

### Interpretation

• Adults PI: 8-11 Underweight | 11-15 Normal | 15-17 Overweight | >17 Obese
• For infants/children, a value of between 2.2 and 3 is considered normal.

Unit system
Weight
Height
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Weight
Height
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Steps on how to print your input & results:

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.

## Ponderal Index Explained

The Ponderal Index, also known as the Corpulence index is a measure of body composition first proposed by Rohrer, a Swiss physician, in 1921. Ponderal index is considered as an improvement over BMI. The weight (or mass) is normalized with the third power of body height, rather than the second power, as is the case for the Body Mass Index (BMI).

There is a formula for adults and one for infants/children:

• `Adult Ponderal Index = Weight in kg / Height3 (m)`
• `Infant/Child Ponderal Index = 100 x Weight (grams) / Height3 (cm)`

### Interpretation

• For adults the a value of PI between 11 and 15 is considered normal weight.
 PI Classification 8-11 Underweight 11-15 Normal weight 15-17 Overweight >17 Obese
• For infants/children, a value of between 2.2 and 3 is considered normal.

More complex interpretation of PI values requires data on sex and gestational age and comparison to reference data.

Compared to the BMI, the PI has higher sensitivity and specificity and is considered to yield valid results even for extreme values.

The infant formula is used in pediatrics to assess whether the newborn baby is malnourished, healthy or overweight.

### Limitations of the ponderal index

• The PI is not an absolute measurement, but an indicator;
• It doesn’t account for body builds with more muscle so a person with a lot of muscle may be classed as overweight based only on weight and height proportion, not on muscle or fat percentage;
• It does not differentiate between body types with different fat disposition, for example between males and females.

## References

### Original reference

Rohrer F. "Der Index der Körperfülle als Maß des Ernährungszustandes". Münchner Med. Wschr. 1921; 68: 580–582.

### Other references

C du V Florey. The Use and Interpretation of Ponderal Index and Other Weight-Height Ratios in Epidemiological Studies. J Chronic Dis. 1970; 23(2):93-103.

Barker et al. The relation of fetal length, ponderal index and head circumference to blood pressure and the risk of hypertension in adult life. Paediatric and Perinatal Epidemiology, 1992; 6(1).

Specialty: Fitness

Year Of Study: 1921

Abbreviation: PI

Article By: Denise Nedea

Published On: June 5, 2020

Last Checked: June 5, 2020

Next Review: June 5, 2025