How many rectangles of any size (including squares) are there in an 8-by-8 checkerboard?

Question

I already know how many squares there are.
I just need a formula or an explaination on how to find out the number of rectangles.
*There are 1,092 rectangles

Answer 1

This is a stumper:

I derived an equation:

n=sum from (i=1 to 8)of the sum(j=1 to 8) of (9-i)*(9-j),
where i and j are the number of line segments on the the horizontal and vertical sides of the rectangles respectively.
I believe this produces all possible sizes of rectangles positioned in all possible spots on the board. A simple check is i=1, j=1 is a single sided rectangle which gets positioned 64 times. i=8, j=8 yields a rectangle that is the size of the board positioned 1 time. Other checks are 1x8, which is 8 collumns, and so on...

but this yields1,296 rectangles.

After further research, I found the following formula:
[(n)(n + 1)(m)(m + 1)/4].
for any matrix. Plugging in 8X8, you get 1,296
I contend that 1092 is the number of rectangles that are not squares.

If you find a different derivation or this is correct, please let me know because I'm ready for prozac now.