What size envelope can i mail with a stamp

In the United States, the United States Postal Service (USPS) allows you to mail a letter or card with a single stamp (currently priced at $0.55) as long as it weighs 1 ounce or less and meets certain size and shape requirements.

Here are the specific dimensions for a standard letter-sized envelope that can be mailed with a single stamp:

• Length: Up to 11.5 inches (29.2 cm)
• Height: Up to 6.125 inches (15.6 cm)
• Thickness: Up to 0.75 inches (1.9 cm)

Additionally, the envelope must be rectangular in shape and have a flat, smooth surface that can be easily processed by automated mail sorting machines.

If your envelope is larger or heavier than these dimensions, you'll need to use additional postage or a larger envelope that meets the USPS's "large envelope" or "flat" size requirements.

Here are some examples of items that can be mailed with a single stamp:

• Standard letter-sized envelopes (e.g., 9x12 inches)
• Small greeting cards
• Small packages (e.g., 1-ounce packages of small items like jewelry or candies)

However, if you're mailing a larger or heavier item, you'll need to use additional postage or a larger envelope. For example:

• Large envelopes (e.g., 12x15 inches) require additional postage
• Packages that weigh more than 1 ounce require additional postage
• Items that are irregularly shaped or have unusual dimensions may require additional postage or special handling

To determine the correct postage for your item, you can use the USPS's online postage calculator or consult with a postal worker at your local post office.