I have got a chart that gives the dilution ratio of water to uncut spirit to obtain a desired proof or abv%. The problem is that it just doesn't seem to be as accurate as it needs to be.

Does anyone have a formula that would allow you to input the uncut proof and then the desired proof? Ideally, this would give an answer in percentage as to what the dilution ratio should be. To explain further, 188 proof or 94% abv would require water to be added in the amount of 142% of the uncut spirit. ,1000ml uncut would require 1420ml of water to be added to bring the proof down to the desired 80 proof,.

I personally can't figure out how to write the formula to where I could use it with a handheld calculator. A formula like this would be ideal regardless of the measurement and the volume.

Thanks Bob, it does help but is a little confusing. I looked there a week or two ago and never saw that calculator. I will have to fool around with it a little.