The maximum size envelope that can be mailed for one stamp varies by country. In the United States, for example, a standard letter must weigh up to 1 ounce and fit within specific dimensions: a maximum of 11.5 inches in length, 6.125 inches in height, and 0.25 inches in thickness. Envelopes exceeding these dimensions or weight would require additional postage. Always check with your local postal service for the most accurate and up-to-date information.
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
For a standard size envelope it is 44 cents.
3 1/2" x 5" (inches) is the smallest legal mailing size for an envelope in the US.
It is not the size of the envelope that matters, it is the weight - it is probably best to have the package weighed at the Post Office to obtain the correct postage.
The largest size envelope that can be mailed with a 45-cent stamp typically falls under the category of a "letter" by USPS standards, which is up to 11.5 inches long, 6.125 inches high, and 0.25 inches thick, weighing no more than 1 ounce. For larger dimensions or heavier weights, additional postage would be required. Always check the current USPS guidelines for any updates or changes in pricing.
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.
US Mail standard envelope up to 1 ounce in weight needs a 42 cent stamp (or any combination of stamps that total 42 cents.)
One normal Canadian stamp (for a letter size and weight)
It depends on the size, weight, number and destination
one ounce.
You can typically mail one letter-size page in a business envelope with one first-class stamp. If you include additional pages, the envelope may exceed the weight limit for a single stamp (1 ounce). For every additional ounce, you'll need to add more postage. It's always best to check with your local postal service for the most accurate and current guidelines.
11 1/2 inches by 6 1/8 inches