I am letting my calves out for a little milk so that they continue to grow into bulls. Right now they are about 17.5 inches. Actually, for all little calved people, you are shit out of luck. Calves are determined by genetics. I usually end up working calves about 15 times a year, three straight sets of standing calf raises. If you want to reach your potential, you must understand that calves are a muscle, and that muscles respond best to shorter high intensity workloads like strength training. Running, cycling, judo, walking on tiptoes, etc... will not build your calves to their potential. Lift heavy weights, full range of motion, toes straight ahead, make them strong and make them work. 3 sets straightleg, 3 sets bent seated. Do not bounce through the movement, push through the movement.
If you don't have big calves, blame your parents.