i am doing some resleeving and some wiring extensions. i need to know the correct wire gauges for the fan tail wiring and the regular molex wiring. that way i wont end up buying wire i can't use. thanks in advance for your help.

I think molex wire is around 20 guage but i have no clue for the fan wire.
Best way is to bring a piece with you when you go shopping

Edit: unless you buy online