I believe it's actually a bit less than 2" x 4" due to "shrinkage".   And not the kind of shrinkage George Costanza faced in another classic Seinfeld episode.  

That dreaded shrinkage ... Michael Jacobs and Ryan Huggins - Thousand Oaks, CA 

This is all the more reason to demand a discount. We are gettting gypted! For the PC Crowd use 'taken'. I don't mean to denigrate the gypsy real estate agents out there.

It is amazing the things that we refer to by a standard measurement  that no longer applies.  

1.5 x 3.5 I guess they round up as you say. You don't get what you pay for.

Actaully it is smaller than that. The wood is cut wet if it is thin it is warped... I am having fits with my redwood fence. The fence guy mentioned HD fencing material is not good so he charged me premium and I found he went back to HD. The board will warp 2-3" over 8 ft. You turkey.

And you thought learning the metric system was a chore.

Thought the smaller side was a bit bigger, like 1.75"!

Thank you.

I forgot, but I know it's less than 2 x 4.  Maybe 1/2 inch on both sides.

1.5 by 3.5. I remember years ago when it was much closeer to the stated 2x4 size. 

LESS than 2" x 4" - by about 1/2" both ways I think

Mind = blown.

I actually knew this!

As with so many things in life, it is much less than advertised.

Another easy question, thanks Barbara

1 1/2 X 301/2

Once again late to the show

Next question what is Rough Sawn ;)

Thanks for the lesson.

Barbara Todaro - thanks for the answer, usually I am here late at night.

 1/2 inch less

You know your stuff. 

I always wondered about this!  Shrinkage?  Who knew?

The finnished product is as you say

Wow, did not know that Barbara.

Depends where you buy it, get some seconds at the mega store and can be from 1 3/4 by 3 3/4 to 1.5 by 3.5 and if your lucky, it does not bow like, well a bow.