Leo is absolutely correct. I would, however, like to add that what you enter is not gospel. You won't see much difference between feed rates of 100, 110, or 125 inches/min. Or 15,000, 18,000, or 20,000 RPM. When you are cutting wood, you want a feed rate that is high enough and an RPM that is low enough that you get chips and not dust. This may not be possible with ball nose or V bits, as the different diameter parts will cut differently. (The tip is effectively zero diameter.)
There may be a sweet spot for RPM that reduces the noise.
Small end mills will break with too high a feed rate.
Many machines won't actually move at their maximum feed rate when cutting some projects, the stepper motors can't get them up to speed fast enough before they have to change direction.
If your plunge feed rate is low, any movement that changes the Z will feed at that low speed. For example, a long sloping cut up or down.
Setting Z2 in the material setup to a fairly small value (maybe .06") can speed things up on jobs with a lot of Z movements.
Bottom line: If an experienced operator who is familiar with your machine and the material to be cut has half an hour to fool around, they can probably come pretty close to the best numbers for a new, different project. The rest of us settle for something that works without causing problems. If we have time and the need, we'll tweak a bit to see if it improves things.
Good judgement comes from experience.
Experience comes from bad judgement.