Russian tortoise growth rate

[asterophora]

I have a captive bred male(?) Russian tortoise, he's about a year and a half old now and already 4 inches! Is this normal and okay or should I be doing something differently? I know that male Russian tortoises usually only get to 5-6 inches but that you can't tell a tortoise's sex until are a certain age but it can be affected by the temperature they are incubated at, which is why mine is presumably male according to the breeder. Everything I can find online makes it seem like there's not really a linear growth to age timeline and that it all depends on their environment but does it mean that his environment is good if he's growing fast?

 

[Tom]

4 inches at one year is pretty normal.

There really can't be any meaningful average because growth rates vary wildly and for many reasons. If all is going well, then 4 inches at a year is pretty darn good.