Originally Posted by Adam Smith

You're wrong. dr_torch's calculation is essentially correct. I built a calculator spreadsheet (with help from some others) for exactly this purpose: https://www.flyertalk.com/forum/air-...les-aqd-4.html

Just use it (or the version Jack linked to earlier) and you'll know within a very small margin what the AQD will be for each segment.

This has worked just fine for me on plenty of non-AC-stock tickets, including those involving several carriers (e.g. AC, UA, CM and AV).