well it really depends on the cham. I think you should put a cup in his cage with crickets, count how many are in the cup. once he approaches the cup and eats his first cricket, time him and leave it there for atleast 15 minutes. when he stops eating he is full and that should be how many crickets he should be eating. I have two veileds and they are 3 months old. my male eats about 15 cricks a day and my female about 8-10. the cricks are 1/8th of an inch.