3.5 inches by 5 inches
I mailed one out and it seemed to work. Anything smaller will be kept by the post office or returned to sender.
3 1/2" x 5" (inches) is the smallest legal mailing size for an envelope in the US.
Australia is the smallest continent, with an area of 7,686,745 square kilometres (2,967,894 square miles).AustraliaAustralia is the smallest contient
14cm X 9cm is the smallest legal size for a letter.They have all the information for parcel and letter size on their site: http://www.canadapost.ca/cpo/mc/personal/productsservices/send/lettersdocuments.jsf
Vatican City is the smallest with only .17 square miles.
I know the post office has to hand process square sized envelopes. Their machine has a hard time locating the stamps location because of the envelopes size. I have mailed square envelopes a lot of times. If mailed within the U.S., it's $0.03 more than the standard $0.44. So it is 47 cents....that is- if it is the normal weight of a card or letter. If it's over an ounce, the price goes up.
an 8x8 envelope is charged "parcel rate"..because it is square and over the letter size dimension...cant be a "large envelope" because it is not rectangular
For a standard size envelope it is 44 cents.
What is the standard-size large envelope?
Square EnvelopesSquare envelopes are subject to the $0.20 nonmachinable surcharge.As of May 11, 2009 a regular first class stamp is $0.44 so postage for a square envelope is $0.64Technically, the 6 1/4 x 6 1/4 size classifies the letter as a "Large Envelope" (smallest dimension > 6 1/8 inches), but since it is so close (1/8" !!) they may not enforce the higher Large Envelope rate.See the post office website for more information: http://pe.usps.com/text/dmm100/postage.htm
The largest letter that can be mailed with a regular stamp is 11 1/2" X 6 1/8." Further info can be found on the official USPS page at: https://www.usps.com/send/can-you-mail-it.htm?#3
1mm2 1 million square metres
The world's smallest desert is Carcross Desert in the Yukon. It is barely a square mile in size.