I brought my leopard about 2 years ago from a pet shop - I know they are meant to be slow growing, however I'm worried as other leopards that are the same age are twice the size !!
pictures of your enclosure are also helpful. if you want to give us a reference of how big he is by holding him in your hands that helps.
leopard tortoises like most tortoises grow at different speed some start out slow and then take off. some start out fast and then slow down. you don't want to get confused between one that's not growing because it's a slow grower and one that is sick so I'm glad you asked for opinions.
As has been said they grow at their own rates. What you want to watch for is steady growth at whatever rate. I weigh mine about weekly to make sure the trend is always up. It fluctuates, so one week they May lose a little, but overall weight is increasing.
How you house them and diet affect the growth rate. Share more info on your care, and we can offer suggestions to improve,
Welcome to the forum.