3 1/2" x 5" (inches) is the smallest legal mailing size for an envelope in the US.
Size 13 envelopes are 98 mm x 171 mm
An A6 envelope is in between an A5 envelope and an A7 envelope regarding sizes. Generally, an A6 envelope is 4 3/4'' x 6 1.2''. You will be able to find these at most stationary stores with the dimensions on them.
The standard size of an A6 envelope is 4.75 inches X 6.5 inches. If that is too large for your car, consider an A2 envelope that measures 4.375 inches X 5.75 inches.
The size of letterhead used in Europe is ISO A4, which is 4.25 x 8.625 inches. The dimensions of an A4 envelope is 324mm x 229mm.
What is the standard-size large envelope?
A legal size envelope typically measures 9.5 x 14.5 inches and is commonly used for sending legal documents, contracts, and other important papers that do not fit in a standard letter-size envelope. It provides a larger and more secure option for mailing important documents.
9 and 12 are.
The standard size business envelope is the number ten. The number ten envelope is open sided with a commercial style flap.
The two classifications of dimensions are Size Dimensions, and Location Dimensions. Size Dimensions are placed in direct relationship to a feature to identify the specific size. Location Dimensions are used to identify the relationship of a feature to another feature in an object.
An envelope can never be too large for itself.
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