I use tobacco flavorings, as a single flavor from .5 to 6% depending on concentration and in one mix at .03% . There's simply too much range to guess at. I have ended up making mixes where I remixed them, started off with 20 ml and ended up making 5 bottles from that, it was so strong (and kept getting stronger). Couldn't just add base to the bottle, wasn't enough room, and I didn't need it all immediately. Could have pitched it but no need. The main thing is to get something mixed you can try and/or let steep.