Cutting Subfloor hole for Toilet Flange

Hello Everyone,

How big should the hole be for this flange? It is a 4X3 closet flange, and i need to cut a hole in the subfloor.

Thanks in Advance,
Molo

Just large enough for the flange to fit through. It doesn't have to be an airtight fit, but you want to have as much subfloor under the flange as reasonably possible for support. Please understand that the flange is to set on top of the finished floor, not on the subfloor. The screws that hold the flange down should go through the finished floor and the subfloor.