Can mail 1.1 ounce letter with one stamp

According to the United States Postal Service (USPS), a First-Class Mail letter weighing up to 1 ounce can be sent with a single Forever Stamp, which costs $0.55 as of 2023.

However, if your letter weighs more than 1 ounce, you'll need to add additional postage. The USPS charges an extra $0.20 for each additional ounce, up to a maximum weight of 3.5 ounces.

Here's a breakdown of the postage rates for First-Class Mail letters:

• 1 ounce: $0.55 (1 Forever Stamp)
• 2 ounces: $0.75 (1 Forever Stamp + $0.20)
• 3 ounces: $0.95 (1 Forever Stamp + $0.40)
• 3.5 ounces: $1.15 (1 Forever Stamp + $0.60)

So, to answer your question, if your letter weighs exactly 1.1 ounces, you would need to add an additional $0.10 in postage to the standard 1-ounce rate. You could use a combination of stamps or a single stamp with a postage due sticker to cover the extra cost.

Keep in mind that these rates are subject to change, so it's always a good idea to check the USPS website or consult with a postal worker for the most up-to-date information.