Hi Everyone, I have been using this formula for my descend now in infinite flight, but it seems to always fail to the point where I still have more feet to descend (by the odd -5000ft perhaps). This leads to me adapting the plan before I land which I find stressful . Any improvements I can make?

Formula for Descending:

- Cruise Altitude – Final Approach = Amount of Descend
- Amount of Descend / Rate of Descend = Descend Time
- Speed of Descend/ 60 min = Nautical Miles per minute
- Nautical Miles per Minute x Descend Time = Start of Decend

e.g.

35000ft/600ft = 58 minutes

250kts/60min = 4.17nm

4.17nm x 58 = 242nm start decend

Decend rate -700fpm (100fpm more for safe decend)