OMG, you people are so cool it makes me wanna cry...
Davegior, looks like your calculator is Windows dependent so I can't run it, I'm still on an older Mac for a little while longer. An Excel version would be platform-independent, just a suggestion you might want to think about to help my particular minority, I'm not the only one...
Kim, you're in my head! Shane's reverse calc is the exactly the concept I was looking for. Further enhancements ideas: an optional "tweaking" entry line to use drops for flavoring, as that's so common for adjustments? Or a converter section with drops:ml:drops? (I tried to add that myself on the earlier version of the calculator, scaling down) Heck, while I'm sharing my wish-list, the ideal calculator for me would handle both very small batch increments (for experiments, drops) and then some way to take your final perfect recipe and scale it up to whatever size you want, 6-10ml or larger... Maybe easy for the math whizzes, too hard for me...
I think a lot of people would like to track how many mgs they're consuming as they transition over time, so knowing your strength
results really helps after perfecting a recipe, for projecting the quantity of
juice supplies you'll need, because so many people need to plan ahead with mail order, finances, etc. Not to mention which sales to take advantage of and how big your order should be! I really try to consolidate orders and minimize wasted $ spent on shipping (for environmental reasons also, that's just me). It's the One-Stop concept after all.
BTW Kim, last night I discovered I couldn't put 10 of the 5ml pipettes into my shopping cart, seems you don't have that many in stock right now! Shopping cart said to "try another number." Vendors have the same inventory-management challenges that individual DIYers do, I'm sure.
I'm getting slammed for time with a road trip coming up soon (there's that planning-ahead factor again!) but I just LOVE LOVE LOVE the people here, thank you all so much... I probably can't dig deeper into all this until I get a nice chunk of undisturbed time to concentrate, maybe not until Labor Day weekend, holiday respite you know

... I've learned, never mix in a hurry!
Hopefully some others will chime in about their own precision-measurement needs and the solutions they've found, or what else they need for math help, then this
thread will be the ultimate go-to Sticky BOMB!
Rock on ECF and One Stop DIY! Keep the great ideas coming and thanks again to everybody as we all try to help each other out!