Envelope size

[bar_tomk]

When calculating shipping prices. There is space for three numbers for envelope size. I put in the numbers that are on the envelope box -  but not accepted. 
This is the envelope size

9 1/2 x 8 x 11 5/16

[buyselljack2016]

maybe use whole #'s. No fractions.

That is a "huge" envelope.

[redmodelt]

You have to use whole numbers, so it would be 10X8X12. That is not an envelope size, that would be box size, besides the fact that even if it was, you would need to measure the thickness with the item inside, not just copy some numbers off the box. I think you are ticking a wrong service when setting up shipping.