I wouldnt just go off what everyone else is using
Goto autozone they have tons of them different lengths wrap a rope around measure it to get a rough measurement. Keep the reciept and get it perfect by setting the tensioner almost to the tightest extreme limit mark because if you have mods and extra power with aftermarket under drive pullys it will stretch out after about 100 miles of use then be perfect.
I made the mistake of setting it to the loose or mid limit and after it stretched I was getting poor pully traction under high RPM.