How much to ship a square envelope?

[highheels]

My invitations are 6 X 6 so I will likely have to buy envelopes slightly bigger. Looking at USPS.com if the height of my envelope is more than 6 1/8 (which is an envelope size I can't seem to find anywhere online) it is considered a package. Has anyone mailed a similar sized envelope? How much were you charged per enevelope.

 

I am aware that for a sqare there is an extra charge of .17 per envelope.

thanks for your help!

[TammyWright]

$0.58

 

i think...i just sent a bunch out and that is what i put...you can buy stamps with that exact amount at the post office or on stamps.com