Amputee BMI Calculator
Accurate Body Mass Index calculation adjusted for limb loss
Imperial (lbs, ft/in)
Metric (kg, cm)
None (Standard BMI)
Hand / Wrist Disarticulation (0.7%)
Below Elbow (2.3%)
Entire Arm / Shoulder Disarticulation (5.0%)
Foot / Ankle Disarticulation (1.5%)
Below Knee (Transtibial) (5.9%)
Above Knee / Entire Leg (16.0%)
Your Results
Estimated "Whole Body" Weight:
–
Adjusted BMI Score
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–
Underweight
Normal
Overweight
Obese
*This calculation uses the Osterkamp formula to estimate what your weight would be without limb loss, providing a more accurate BMI assessment.
Why Use an Amputee BMI Calculator?
Standard Body Mass Index (BMI) calculations are based on the relationship between total body weight and height. For individuals with limb loss, a standard calculation often yields misleading results. Because a limb accounts for a specific percentage of total body mass, an amputee may appear "underweight" or have a lower BMI purely due to the missing mass, even if their remaining body composition is healthy or overweight.
This calculator adjusts for amputation by estimating your "whole body" weight before calculating BMI. This provides a more clinically relevant metric for assessing health risks associated with weight.
How It Works: The Formula
To calculate Amputee BMI accurately, we first determine the Estimated Body Weight (EBW). This is done by taking the current weight and dividing it by the fraction of body weight remaining.
Estimated Weight = Current Weight / (1 – % of Limb Lost)
Once the Estimated Weight is determined, the standard BMI formula is applied:
BMI = Estimated Weight (kg) / [Height (m)]²
Percentage of Body Weight by Limb
We utilize standard medical proportions (Osterkamp method) to determine the weight percentages used in the calculation:
| Body Segment | % of Total Body Weight |
|---|---|
| Hand | 0.7% |
| Forearm (Below Elbow) | 2.3% |
| Entire Arm (Shoulder) | 5.0% |
| Foot | 1.5% |
| Lower Leg (Below Knee) | 5.9% |
| Entire Leg (Above Knee) | 16.0% |
Understanding Your BMI Result
While BMI is a useful screening tool, it does not measure body fat directly. For amputees, maintaining a healthy weight is critical not just for cardiovascular health, but for the fit and function of prosthetics. Significant weight fluctuations can cause sockets to fit poorly, leading to skin breakdown or mobility issues.
- Underweight (BMI < 18.5): May indicate malnutrition.
- Normal Weight (BMI 18.5 – 24.9): Generally associated with lowest health risks.
- Overweight (BMI 25 – 29.9): Increased risk of developing health issues.
- Obesity (BMI 30+): High risk of cardiovascular disease and diabetes.