Financial Calculators

Ponderal Index Calculator

This ponderal Index Calculator will provide a more accurate measurement than Body Mass Index.

Ponderal index formula

Child or adult?

Table of contents

Ponderal Index Formula
Normal range of the Ponderal Index
Infant ponderal index
How to use the calculator for the ponderal indicator
If you need a more exact measure, Body Mass Index, you can also check this ponderal-index calculator. The ponderal or Rohrer’s index (also known as a corpulence or Rohrer’s index) can help you determine whether or not you are obese, overweight, or just right. However, the PI has greater sensitivity and specificity. So if you are tall, it may appear that your BMI indicates you are obese. Pediatricians use the infant ponderal indicator to assess whether a newborn baby's health, nutrition, and weight are correct. You can read on to learn about the formulas for ponderal and the normal ranges of ponderal.

Ponderal Index Formula

Ponderal can be interpreted as estimated, or ascertained from the weight. The ponderal index can be described as an improved version of the body mass index. BMI uses height up to the second power.
BMI = weight / height^2
While the ponderal indicator uses height3, this makes more sense, as our bodies have 3-dimensional structures rather than 2D.
PI = weight / height^3
BMI works well if someone is of average height (5ft 6in/170 cm), but a high BMI value will likely indicate an overweight person. BMI is a positive measure that shows normal weight for someone who is short.
For adults, the basic weight unit for PI calculation is kilograms and height in meters. Infant and newborn babies' weights are often expressed in grams. Height is typically expressed in centimeters.
PI (adult) = weight (kg) / height (m)^3
PI (child) = weight (g) / height (cm)^3 = 0.1 * PI (adult)
As you can see, there is a difference in Rohrer's indices of children and adults. It is rare that the children's index is calculated using the standard adult-ponderal index formula. If it is, it might be 23 instead. To make things more difficult, the corpulence indicator can be differently defined. The most simple and well-known equation was used in our calculator for the ponderal index. Therefore, it is highly likely that it will be able to meet your expectations.

Normal range of the Ponderal Index

12 is considered the norm or average value for adults' ponderal Index, while 2.4 (24) applies to a newborn or infant. The normal ranges for ponderal indices are also defined as:
11-15 for adults – values derived by BMI for the reference height (170 cm); sometimes 11-14 range is used
2.2-3.0 for newborn babies. A simplified, generalized normal PPI range. It does not matter how many weeks you are gestating, what sex the child is having, and what maternal parity.
BMI and Pi aren’t perfect measurements because they don’t differentiate between muscle and fat. BMI and/or PI can both be the same for a muscular athlete or a smaller man. Remember, PI is only an indicator and does not represent your overall health.

Infant ponderal index

Infant ponderal is used for determining whether newborn babies have malnutrition, normal weight, or excess. It's also used to diagnose impaired fetal growth. It allows you to identify whether the intrauterine restriction of a child's growth is symmetrical, normal, or asymmetrical (lower PI).
The calculator will display the value of PI to the newborn. But, it's not possible to assess its nutritional status. It depends on many other factors, including gestational ages, neonatal sex, and maternal parity.

How to use the calculator for the ponderal indicator

If you still have questions about how to determine the Ponderal Index, take a look at this step-by-step example.
Pick the person for whom the calculations are to be done. Select either an infant or an adult. Let's pretend that we need to calculate the PI of an adult. So the formula for the ponderal indicator for an adult is used.
Enter your height. Assume the person is 6'6". It's easy to change units by clicking on the unit name.
Select the weight. For example, 195 pounds.
Corpulence is shown along with the information about you. In this case, it is 13.97. This gives you a healthy range.

Parmis Kazemi
Article author
Parmis Kazemi
Parmis is a content creator who has a passion for writing and creating new things. She is also highly interested in tech and enjoys learning new things.

Ponderal Index Calculator English
Published: Mon May 16 2022
In category Financial calculators
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