Common questions about using this calculator.
Is corrected BMI more accurate than standard BMI for everyone?
No — it's specifically intended for people with limb loss. For non-amputees, standard BMI calculations are already accurate to the assumptions built into the formula.
What amputation levels does this support?
Above-knee (transfemoral), below-knee (transtibial), above-elbow (transhumeral), below-elbow (transradial), foot, and hand amputations — set independently for each limb, so mixed presentations (e.g. a below-knee amputation on one leg and an above-knee amputation on the other, or bilateral arm loss) are fully supported.
Why does the calculator ask for pre-amputation height?
Height is used to calculate BMI regardless of amputation status — BMI has always been based on standing/intact-body height. If you don't know your exact pre-amputation height, your best estimate is fine. This is especially relevant for bilateral lower-limb amputees, where a current standing or prosthetic-assisted height measurement won't reflect true stature.
Should I use this instead of talking to my care team?
No. This tool is meant to support informed conversations with your physical therapist, occupational therapist, or physician — not replace their assessment. It's an educational and reference tool, not a diagnostic device.
Where do the correction percentages come from?
They're derived from published anthropometric body-segment weight research (the Winter/Dempster segment tables), which estimate what percentage of total body mass different limb segments typically represent. Full citations are on our Research & Method page.
How accurate is the "corrected" BMI number?
It's an estimate, not an exact measurement. Body composition varies between individuals, and the segment-weight tables are population averages. Corrected BMI is meant to be a better reference point than uncorrected BMI, not a precise clinical measurement.
Is my data stored anywhere?
No. The calculator runs entirely in your browser — your height, weight, and amputation details are never sent to our servers or stored. See our Privacy Policy for details.
Is this calculator free?
Yes, and it will remain free. The site is supported by display advertising, not by charging users.