Divide distance between points by 1500 to 2000 for flight time in hours, add 30~60 minutes for combined passenger loading and disembarking time, take-off, and landing.
Unless something crazy happens, you can figure 2 hours or less from passenger loading to walking out the other airport for any point in what was the USA to any other point in what was the USA. Of course, customs could delay you longer.
LA to other Cities