I think I've already posted here, and realise am probably the exception not the rule as have no doubt above posters have put in solid efforts to grow them with little return.
Left is 21yrs old 72kg, right 41yrs old and 98kg.
Biggest difference I found was not going heavy, alot of walking, obviously overweight people have larger calf muscles just from weight carrying and cycling 45mins daily consciously flexing the calves on each revolution. Takes some getting used to. But worked for me.
Pity my arms wont grow though