I made a calculator in excel to make dilution ratios easier to calculate: It' will work with: 1:14 - single developer ratios (ie. Ilfosol S) and 1:2:100 - a/b solution ratios (ie. PMK Pyro) Also included a simple ml. to US FL oz. and US FL oz. to ml. calculator just because it could be useful. http://www.mikefiction.com/calc/DilutionCalc.xls You can change the volume to any amount and it will re-calculate the ratios. That's kinda why I added the ml - oz conversion That way if I'm using my combiplan tank, it's 36 US fL oz, so I convert that to ml, which is 1064.65 - then type the ml amount 1065 into the Target Volume field on the dilution calc and it recalculates for that volume. So it'll work on any tank.