Are there any sado-mathematicians a***rd?

I have a riddle.

If you convert a positive integer from base *0 into base B, how can you predict in advance exactly how many digits the base B integer result will have?

For example, if I converted the base *0 integer *84*65270***227* into base 7, how many digits would that base 7 integer have?

What if I converted it into base 2 or *6 instead of 7?

What is the general rule for predicting, in advance, the number of base B digits in the converted integer?




Please don't kill me.

LOL