Size Help? Gates Green Stripe Belt

Need help with belt size please.

Metco 2.8 SC pulley
Metco Idler Pulley 5 piece Kit with Idler Bracket (1) 90mm + (3) 100mm
Stock alternator pulley
Stock lower

After looking a charts and making a few calls I came up with 75" and a couple sites tell me 76" not guaranteed and said go with a few different sizes just in case.

Anyone have this pulley set up out there? should my middle starting point be 75'' or 76"

Thanks

73.50
Add 1" for idler
Add .5" for each 90mm to 100mm
Should be 76"

.5 for each. oh okay cool

Thanks