Using simple numbers can help determine an unknown formula, sometimes. While there are easier formulas I am sure, I am just going to “reverse engineer” this one with the data I have.

In that example, I have a 2:1 ratio (3 parts total) with a final volume of 10fl/oz.

10floz / 3 parts is ~3.3 per part. 2 * 3.3 = 6.6, 1 * 3.3 = 3.3

6.6 + 3.3 = 9.9 (close enough…)

So, what we do is determine what is “one part” of the mixture, and then do some basic math on the given ratio.

Say I’m diluting a chemical at 10:1 (that’s 11 total parts) for a final volume of 240 ml. 240 ml / 11 = 21.8 ml of chemical. Now to find the water: 240 - 21.8 = 218.2 ml.