I thought I’d share a quick tip.
I’ve always used my Distance to Destination on IF to calculate my decent rate (Making sure i’m at 18,000ft @50nm from the airport prior to contacting approach) but sometimes the distances haven’t matched up.
I now use IFATC.Org, find the airport that i’m heading too and click on the Number of Total A/C inbound. Then scroll down to find your callsign. There it will give you an exact distance to the airport.
See pictures for an example.
Hope this helps some people out.