I have a question regarding how RDM/Elite Bonuses are calculated. Assume, for the moment, that I have booked a fare (A/C/D/J/Z) that earns a 150% RDM bonus (calculated based on BIS base earning), and that would also earn a 225% Plat Bonus (which I believe is calculated against BIS, rather than an RDM-bonus-adjusted amount). For the purpose of simplicity, assume the BIS earnings for this fare is 100mi (ignoring the 500mi minimum earnings). Some logical/mathematical steps have been abbreviated/omitted.

Here is how I would calculate the total bonus earnings:

100 BIS x 225% (Plat Bonus) = 225mi.
Additional RDM Bonus Calculation: 50% of 100 BIS = 50mi.

The sum of 225 and 50 is 275, yielding the actual earned RDM amount for this theoretical flight. (i.e., the Plat Bonus is calculated as against BIS earnings of 100mi rather than the RDM-bonus-adjusted figure of 150mi.).

Is this correct, or does the bonus earning calculation look like:

RDM Bonus applied to BIS of 100mi: 100 x 150% = 150mi.
Plat Bonus applied to adjusted amount: 150 x 225% = 337.5mi

Which of the two is correct? If neither, what is the correct calculation method?

The bonus miles look to calculate against the BIS miles from what I can tell by looking at both my records and the wife's. Note that this also applies to minimum mileage, whereby the bonus is calculated on the BIS, rather than the minimum mileage.

According to the calculator on co.com the 50% CoS RDM bonus is on 500 mile minimum, not actual miles. The 125% bonus is on actual miles with no minimum.

A flight EWR-DCA (214 miles) in A will earn 750 EQMs, 500 "Base" RDMs, 250 "CoS" RDMs and 268 "Status" RDMs, totaling 1018 RDMs.

Each bonus is calculated against the base number, not stacked like you tried in your example B. Your A is wrong because the CoS bonus has the 500 mile minimum, not BIS.

Hope this helps.

For the purposes of the question posed above, I chose to ignore 500mi minimum earnings issues, as I wanted to keep calculations simple by using 100mi as the base BIS figure. Thanks for confirming that calculating each bonus separately as against BIS (and then tallying together) is the correct method.

From looking at the calculator on CO.com this is what I gather:

BIS * 125% = Plat Bonus
BIS * 50% = RDM bonus

Take ELP-IAH for example (since it falls outside of the 500 mile minimum).

669 BIS miles
RDM Bonus = 334 (669 * .5)
Plat Bonus = 836 (669 * 1.25)
Total = 1839

As sbm12 stated, the CoS bonus is based on the minimum number of miles (500) or actual BIS, whichever is greater. The elite bonus is based on actual BIS.

For example, BWI-CLE in A yields 500 RDM's (actual BIS is less than 500, so the 500 RDM minimum applies); a 250 mile CoS bonus RDM's (50% * 500); and 392 Platinum elite bonus miles (125% * actual BIS).