How long must wait before take off

Hello everyone,
maybe it’s a stupid question, but how long should you wait, from the moment you power up the system to the moment you take off, to be sure that all sensors have initialized and calibrated?

Thank you for your help

If your system has GPS wait for 3D lock for your home point to be set, it depends on your area of flying, normally it takes around 30 seconds but in cities it can take up to 5 minutes.

Check this out to know when 3D lock is acquired https://ardupilot.org/copter/docs/common-leds-pixhawk.html

If you don’t have GPS on your system you can start flying once gyros and accelerometer are calibrated, normally takes 10 to 15 seconds!

Thank you for your help @Yaros