If you want to understand the basic principles of crop factor, depth of field, and sensor size, then you should check out this video.
If you really like to nerd out over gear, then this is your moment. Blake Evans tackles the myths, misconceptions, and general confusion surrounding depth of field, crop factor, and the differences between full frame and crop sensors. In this very detailed video, as well as in his equally detailed write-up in PetaPixel, he offers illustrations that explain these principles in depth to show you what you need in order to get a true equivalent image from different sized sensors.
As you might’ve noticed, this video isn’t for the faint of heart. It’s geared toward professionals who not only have some advanced knowledge of crop factor and camera sensors, but who also want to fully understand crop factor equivalence, as well as how speed boosters work.