Understanding the USPS Postal Rates

Before the United States Postal Service came out with the Forever stamp, each stamp was given a specific monetary value for its use in mailing letters. Most stamps have their USPS value displayed on the stamp and it is your job to make sure that the stamps you pick for you letter or package add up to the current postal rate for your item.

USPS Postal Rate (as of January 21, 2024)

Postcard - $0.53
(Oversized postcards use Letter Rate)

1st Class Letter (Standard) - $0.68
Extra Ounce - $0.24
--- For Example: 2 ounce ($0.92), 3 ounce ($1.16), 3.5 ounce ($1.40)

1st Class Letter (Non-Machinable) - $1.12
Extra Ounce - $0.24
--- For Example: 2 ounce ($1.36), 3 ounce ($1.60), 3.5 ounce ($1.84)

1st Class Large Envelope (Flats) - $1.20
Extra Ounce - $0.24
--- For Example: 2 ounce ($1.44), 3 ounce ($1.68), 4 ounce ($1.92)

1st Class International Letter - $1.55
Extra Ounce - Depends on Country

Dimensions & Requirements

Postcard:  Length of 5 to 6 inches. Height of 3-1/2 to 4-1/4 inches. Maximum thickness of 0.016 inch.

Standard Letter: Length of 5 to 11-1/2 inches. Height of 3-1/2 to 6-1/8 inches. Maximum thickness of 1/4 inch.

Non-Machinable Letter: Unusually shaped letters (square, vertical, etc) and letters that can't go through the USPS sorting machines cost more to hand cancel. This can include lumpy envelopes, rigid envelopes, and mail with clasps, string, or buttons, or wax seals.

Large Envelope (Flats): Length of 11-1/2 to 15 inches. Height of 6-1/8 to 12 inches. Maximum thickness of 3/4 inch. Flats that exceed maximum dimensions or are rigid, non-rectangular, or not uniformly thick (difference of 1/2 inch) are charged package prices.