Perlite and fox farm soil question

I'm planning on getting soil soon to transplant my plants. My question is for every bag of fox farm how much perlite should I mix in. Is there a pre weighted bag of perlite by any particular company that I can throw in there to give me a good ratio? Thanks

I just use 1 gallon of medium to .5 gallon of perlite. Its really your own preference. You don't even technically need perlite it definitely helps though!

I try for about 1/3 perlite and 2/3 soil, mix very well and it doesn't have to be exact.