When working size of motor required for 4 motor drone do i have to use 4 motors the same thrust or divide thrust by 4?

Take the total weight of the quad, double it, (gives a hover thrust of 50% of total), and divide by 4 for the thrust required from each ESC/motor/prop combination.

Mark.

@Leon_Gates

Good advise by @CF-FZG but IMHO multiply by 2.2 instead of 2 and then round up the figure to suit motor published thrust figures

That extra bit of thrust will give you better manoeuvrability and vertical acceleration

Cheers

Steve