Hey daath - I gave your calculator a try! Seems to work pretty well. I do not measure my nic-liquid, PG or VG in drops - I just squirt from their bottles, of which I have no idea how many drops/ml they yield. Because the flavoring I used is so concentrated, I use drops to measure only the flavoring. I did a test and the Tasty Puff bottles seem to yield about 35 drops per ml. So.... you might want to give the calculator the capability of having separate choices of drops per ml for each ingredient. I could have over-looked it, but I didn't see a way to assign drops/ml for each ingredient. This option would be especially helpful when making small test batches. I like your calculator. It's very easy to use. I'm looking forward to seeing a "I have these flavors" type of search. Thank you for all your efforts!