How far can the p-trap be from the sink drain?

[notaplumber99]

I'm replacing a 37" bathroom vanity with a 30" vanity. The cold water line is 32" to center from the wall, the drainage pipe is 29" to center, and the hot water line is 24" to center. I opened the wall to see if I could move the water lines and drainage pipe to the left to accommodate the the 30" vanity. When I opened the wall, I discovered the drainage pipe is 2.5" to the right of a sewer pipe. If I install the 30" vanity, the sink drain will be at 15" from the wall.

I can move the drainage pipe about 2" to the left without touching the sewer pipe. How far can a p-trap be from the sink drain?

 

[Reach4]

https://terrylove.com/images/pb/tubularptrap.jpg

3.5 inches on at least one p-trap, 3.35 on the drawing here, and 3.25 inches on some others I have seen would maybe be a number you are seeking.

But I am not at all sure what you are asking.