Originally Posted by bedelman
Even better than an Excel macro, I think, is a web script. Nothing to download, nothing to install, no security risks.
So I implemented whirledtraveler's idea in a quick script.
Frequent Flier Goal Deviation Calculator
Comments welcome. Bug submissions are particularly helpful. (Email, via link on my page, may be more useful than numerous posts here.) I'm also happy to add more calculations -- just tell me what you'd like.
Thanks! I've coded it in Excel also. The true value of the formula is when you use it to project forward. For instance, I have three international flights lined up for this year and a few domestics that I've planned in advance. When I put all of the flights that I'm aware of in the spreadsheet, I see that the last time that G(D) goes positive is in April. My first flight is Friday, and I'll be in negative territory until the return flight the next day. Then I go further into positive terrority with a transcon I'm taking next week.
As the year goes on, I'll schedule more and more trips. I'll add them and be able to see just how far ahead (or behind) I am as time goes on.
My G(D) values look like this so far for the upcoming year:
0.00
-172.86
750.16
2818.19
3790.33
3118.63
4638.71
-5105.05
-3615.95
-1656.70
1946.38
617.96
4221.04
-6532.42
-3313.29
-10305.44
-10448.27
-30998.95
-29357.84