4 Inch Toilet Flange Spigot Pipe

[Tom Finlay]

Can anyone tell me what the outside diameter is of the pipe that extends down from a 4 inch (not 4X3) ABS spigot-type toilet flange? Is it the same as Schedule 40 4 inch pipe? [That type of pipe is about 4 1/4 inches O.D., within 1/16", anyway]

Any information will be appreciated! Thanks!