What is a #10 business envelope? Envelopes in this size have a standard height of 4 1/8 inches by a length of 9 1/2 inches. A standard 8 1/2 x 11-inch piece of paper can easily be held in them, which ...

Please note: Letter rates are only for normal business envelopes (sizes #6 or #10), which are no larger than 6-1/8" in height and 11.5" in length. Standard manila envelopes are considered large ...