Quick answer
Ponderal index = weight (kg) ÷ height (m)³. A 70 kg, 175 cm adult has a ponderal index of 13.06 kg/m³.
Enter weight and height. The calculator returns the ponderal index.
Related tools: Ape Index Calculator: Arm span compared with height. BMI Calculator: Find your Body Mass Index (BMI) and weight status. Height Calculator: Convert height between centimeters and feet-and-inches.
How to use the Ponderal Index Calculator
- Enter weight (kg) (between 2 and 500).
- Enter height (cm) (between 30 and 260).
- Press Calculate to see the result, and use Reset to start again.
| Input | What to enter | Allowed values |
|---|---|---|
| Weight | A number, in kg | ≥ 2, ≤ 500 |
| Height | A number, in cm | ≥ 30, ≤ 260 |
Formula and method
Formula
PI = weight (kg) ÷ height (m)³
IEEE-754 double precision; shown to 1 decimal place unless stated.
Ponderal index (Rohrer's index). Informational estimate, not medical advice. Talk to a qualified health professional about your own situation.
Worked examples
This example is verified: each one is an automated test case that the live calculator must reproduce exactly.
Example 1
Inputs: Weight = 70; Height = 175.
| Result | Value |
|---|---|
| Ponderal index | 13.06 kg/m³ |
The first line is the headline result (ponderal index). IEEE-754 double precision; shown to 1 decimal place unless stated.
How it differs from BMI
BMI divides by height squared, so it penalises tall people; the ponderal index divides by height cubed and is steadier across heights. For adults, values of roughly 11 to 15 kg/m³ are common.
Reference ranges
Adults and infants use different reference ranges. In newborns the ponderal index screens for growth restriction. Use it with other measures; it isn't a diagnosis.
How the result changes with weight
Holding every other input at the first worked example, this table changes only weight. It shows how sensitive the answer is to that one value; each row was produced by running this calculator.
| Weight | Ponderal index |
|---|---|
| 35 | 6.53 kg/m³ |
| 70 | 13.06 kg/m³ |
| 140 | 26.12 kg/m³ |
| 280 | 52.24 kg/m³ |
What happens with invalid input
These messages are produced by the calculator itself, so you know what to fix.
- Height: entering "5" shows "Height must be at least 30." beside that field and no result.
Choosing between the Ponderal Index Calculator and similar calculators
Each row shows what a related calculator on this site asks for and what it returns, so you can pick the one that matches your question.
| Calculator | You enter | It returns |
|---|---|---|
| [Ape Index Calculator](/health/ape-index/) | arm span and height | Ape index |
| [BMI Calculator](/health/bmi-calculator/) | units, weight and height | Your BMI |
| [Height Calculator](/health/height-calculator/) | convert | Height |
| [Body Fat Calculator (U.S. Navy)](/health/body-fat/) | sex, height and neck | Estimated body fat |
| [Ideal Weight Calculator](/health/ideal-weight-calculator/) | units, sex and height | Ideal weight (Devine) |
Background: body measurements and screening
Body-measurement ratios are screening tools, not diagnoses. BMI ignores body composition and fat distribution, and reviews find waist-to-hip and waist-to-height ratios are useful additions but not clearly better than BMI or waist circumference alone. Where the tape goes matters, so measure at the same sites each time.
Some sources quote a waist-to-hip ratio above 0.8 for women and 0.95 for men as a marker of increased metabolic risk; treat that as a screening flag, and talk to a clinician about what your own numbers mean.
Assumptions and limitations
- Adults and infants use different reference ranges
- Not a diagnosis
This calculator gives general information based on published formulas. It is not medical advice, and it cannot account for your health history. Talk to a qualified clinician about decisions that affect your health.
If a required value is empty, not a number, or outside its allowed range, the form marks that field with a message and shows no result instead of a misleading number. The automated checks deliberately try invalid entries for height to confirm this.
Frequently asked questions
What is a normal ponderal index?
Roughly 11 to 15 kg/m³ in adults.
Why cube the height?
Weight scales with volume.
Is it better than BMI?
It suits extremes of height.
What does the Ponderal Index Calculator calculate?
Weight relative to the cube of height. It returns Ponderal index.
What formula does the Ponderal Index Calculator use?
PI = weight (kg) ÷ height (m)³. Ponderal index (Rohrer's index).
What do I need to enter in the ponderal Index Calculator?
You enter Weight (kg) and Height (cm).
How is the result rounded or limited?
IEEE-754 double precision; shown to 1 decimal place unless stated. Adults and infants use different reference ranges.
What are the limits of this calculator?
Adults and infants use different reference ranges. Not a diagnosis.
What is an example of a ponderal Index result?
With weight 70 and height 175, the ponderal index is 13.06 kg/m³.
Can I rely on this calculator for a decision?
This calculator gives general information based on published formulas. It is not medical advice, and it cannot account for your health history. Talk to a qualified clinician about decisions that affect your health. For this calculator in particular: Adults and infants use different reference ranges.
Related calculators
- Ape Index Calculator — Arm span compared with height.
- BMI Calculator — Find your Body Mass Index (BMI) and weight status.
- Height Calculator — Convert height between centimeters and feet-and-inches.
- Body Fat Calculator (U.S. Navy) — Estimate body fat percentage from tape measurements (U.S. Navy method).
- Ideal Weight Calculator — Ideal body weight by four published formulas (Devine, Robinson, Miller, Hamwi).
- Waist-to-Hip Ratio Calculator — Waist-to-hip ratio and WHO risk threshold.
Sources
- Common definition used on this page. No single authoritative standard defines it, so the exact formula is stated in the formula section above
Content last reviewed 2026-11-04. Formulas and worked examples are checked by automated tests against independently computed values.