Mourtzakis et al used computed tomography (CT) scans to estimate fat and fat free mass in patients. The authors are from the University of Alberta in Canada.

Examination: CT scan at L3 level



(1) skeletal muscle area in square cm

(2) total adipose tissue area in square cm


fat free mass (FFM) in kilograms =

= (0.3 * (area of skeletal muscle)) + 6.06


fat mass (FM) in kilograms =

= (0.042 * (area adipose tissue)) + 11.2


Hopefully adding the 2 results together will approximate the patient's weight.



• The equation for FFM has an r = 0.94, p <0.001, SEE = 0.72 kg.

• The equation for fat mass has an r = 0.88, p < 0.001, SEE = 0.80 kg

To read more or access our algorithms and calculators, please log in or register.