Amputee BMI Calculator
Calculate adjusted BMI for limb amputees using weight-for-amputation corrections. Adjusts measured body weight by adding back the estimated weight of the missing limb(s).
Results
What is it?
Standard BMI underestimates the true BMI of amputees because the measured weight is lower than pre-amputation weight. Adjusted BMI corrects for this: Adjusted Weight = Measured Weight / (1 − Limb Weight Fraction). Limb weight fractions are based on the Dempster (1955) / Winter segment weight table, widely used in clinical practice.
How to use
Enter current measured weight, height, and select the amputation type. The calculator adds back the estimated weight of the missing segment to give the corrected BMI used for nutritional and clinical assessment.
Example scenario
A patient weighs 65 kg with a unilateral above-knee amputation (16% body weight). Adjusted weight = 65 / (1 − 0.16) = 65 / 0.84 = 77.4 kg. Height = 170 cm. Adjusted BMI = 77.4 / 1.70² = 26.8 (overweight range) vs unadjusted BMI = 22.5 (normal).
Pro tip
This calculator is for clinical nutritional assessment — always interpret alongside clinical judgement. The adjusted BMI may be used to estimate caloric requirements using Mifflin-St Jeor with the adjusted weight, giving more realistic energy targets for amputee rehabilitation.