Calc The Umbrella Academy - Doctor Terminal devours the Rumours arm

Whatever Dr Terminal consumes is turned to energy in order to feed the disease that eats his insides, which drove him an instatable hunger, which only human flesh could satisfy. As seen above, he at least ate The Rumours arm (who was 10 at the time), as well as some doctors. One arm takes up 5.3% of someones total body mass. A 10 year old girl on average weighs 68 pounds, or 30.8443kg. As Dr Terminal also once ate through prison bars, he'd easily be able to eat bone.

M = 30.8443 X 5.3/100
= 1.6347479kg

It's pretty explicitly mass-energy.

E = mc^2
= 1.6347479 X 299792458^2
= 1.46923814e17 joules
= 35.1156343212 megatons

Final Results
Dr. Terminal eats the Rumours arm = 35.116 megatons