This might not be the best place to post this but I'm thinking about trying DIY. I see that I can get liters of 100 nic and gallons of VG. Is there a program that can tell me how much VG I need to make my nic into 12mg. I'm guessing 7 to 1 so it's about 2 gallons of VG for 1 liter of nic. I'm not good going from metric to US gal.