Every airline tells you two hours for domestic and three for international. That is advice about the terminal, not about Los Angeles. The part that actually goes wrong is the drive — and the drive to LAX is not the same journey twice.
Start from the terminal, not the clock
LAX loads from a single horseshoe road. At peak, traffic inside the horseshoe alone can take twenty-five minutes from the entrance to a terminal door. Terminals 1 to 3 sit at the top of the loop and clear fastest; Tom Bradley International and Terminals 4 to 7 are deepest in and worst affected.
Add the real drive time, not the map time
From Santa Monica, a mapping app will say twenty-five minutes. Between 7am and 10am, or 3pm and 7pm, plan for fifty. From Downtown, forty becomes seventy-five. From Pasadena or the Valley, you are crossing the whole basin — add an hour to whatever you are shown.
The single most common reason people miss flights out of LAX is trusting a journey time quoted at 11pm for a trip at 8am.
A working rule
Take the airline minimum. Add the drive time your app quotes for your actual departure time, not for now. Add twenty-five minutes for the horseshoe. Add fifteen more if you are flying from Bradley on a weekday evening, when every international departure leaves in the same three-hour window.
What a chauffeur actually changes
Not the traffic. What it changes is that the pickup is scheduled against your flight rather than against your optimism, the driver is watching the live flight status, and you are not circling a parking structure at the end. For an early departure that is the difference between leaving at a time you chose and leaving at a time you guessed.