GrannieAnnie is right, 6.5 x 2.5. The easiest way to do this math is to take the finished size of the block (6), divide by the number of bars (3) which gives you the finished size of each bar, and know then you have to add a half-inch to each bar for the cut size of each bar.
OOPS!!! That's right if all three bars are the same size, but check these directions and see that the middle one is wider (as mentioned above).
http://www.ashevillequiltguild.org/A...or%20Linus.pdf