- "it takes 3 NM to descend 1,000 feet" - "A general rule of thumb for initial IFR descent planning" ***Source:*** [[IPH Ch3]] Alternatively, > [!quote] [[5 Rules-of-Thumb You Can Use On Your Next Flight]] by [[Bold Method]] > Divide the altitude you need to lose by 300. Also alternatively, > [!quote] [The Smart Way Down](https://www.aopa.org/news-and-media/all-news/2022/march/flight-training-magazine/ol-technique-descent) from [[AOPA]] > Take the amount of altitude you want to lose in thousands. For example, if you’re cruising at 7,500 feet to an airport with an elevation of 1,500 feet, you’ve got 6,000 feet to lose. Multiply six (from 6,000) times three (this is why they call it the rule of threes) and you get 18—the distance in nautical miles at which you should start your descent. #rule-of-thumb