# Combination where length can be anything up to a limit

I was attempting to determine how many different combinations of strings can be created from 37 characters, where the string can be up to, but no longer than 63 characters.

I'm not a math person and was hoping to find a calculator online to get me to the total number of combinations. The trick seems to be the "up to" limit of the length. A one character string counts, a nine character counts, etc., just as a 63-character string would count. I'm thinking this would be some huge number.

P.S. Practically-speaking, I'm curious how many different subdomains I can use with the available character set (commas and "and" excluded): 0,1,2,3,4,5,6,7,8,9,-,q,w,e,r,t,y,u,i,o,p,a,s,d,f,g,h,j,k,l,z,x,c,v,b,n, and m

So a hostname could be any combination of those 37 characters with variable string length up to 63 characters, then the domain name, then the top-level domain. [1...63 characters of the 37].domain.top-LevelDomain .

If I have not misunderstood. You have 37 characters.

"words" with only one symbols are 37, one of each type.

For two symbols you have 37 possibilities for the first one and 37 for the second one and so on

At the end you should have this huge amount of possibilities $$\sum_{n=1}^{63} 37^n$$

• Yeah! I think we're thinking the same thing. Do you know what that number is? Sep 1, 2019 at 22:35
• Oh, what is "n" there? Sep 1, 2019 at 22:37
• Oh, oops, never mind. Sep 1, 2019 at 22:37
• Oh wow, that's a huge number. Sep 1, 2019 at 22:39
• Double never mind, don't worry about attempting to calculate that. I get it. Sep 1, 2019 at 22:40