I can see why this has been a challenge, since most of the time we use the e-
juice calc to tell us amounts of components to use to make a target volume of
juice at some nic level and some flavor %. And with my DIYs, I am diluting 100 mg VG unflavored, so I will need to thin it with some amount of water too, as well as add VG to dilute.
To make this easier, we need to make a couple assumptions:
1. The 24 mg unflavored is just the right viscosity that adding flavor to it is all that is needed to have a juice with the right consistency. If the unflavored nic liquid is PG, this is likely true. If it is VG, then water (or PGA) will need to be added, most likely, in addition to flavoring. Both would lower the final nic level from diluting.
2. We will assume a 10% flavor, and the unflavored is PG, so only flavor is required, no additional thinners.
If we start with 90 mL of unflavored and add 10 mL flavoring, we now have 100 mL of juice (90 + 10) with 10% flavor (10 mL/100mL * 100).
If the unflavored juice was 24 mg, it is now 24 mg (90 mL/100 mL) = 21.6 mg. Actually the unit of nic is mg/mL, but using just mg is fine here because its just a proportionality change.
So a general equation can be constructed.
Let f = final nic level of juice.
Let i = initial nic level of unflavored nic-liquid.
Let vu = volume of unflavored nic-liquid.
Let vf = volume of flavoring
Then f = i * vu/(vu+vf).
So for another example, lets say you have 20 mL of 24 mg unflavored, and you add 2 mL of flavoring. The final nic level will be
f = 24 * 20/(20+2) = 21.8 mg.
Most of us doing DIY do not think about this in terms of amount of flavoring to add, we think about it in terms of % flavor that works well for that flavor, and then let the spreadsheet tell us how much flavor we need to include to get that % flavor. In the above example, 2 mL flavor added to 20 mL unflavored will make 2/22*100 = 9.1% flavor, which is around where most flavors do well.
Good luck!
