How much weight is first class mail

The weight limit for First Class Mail varies depending on the type of mailpiece and the destination. Here are the general weight limits for First Class Mail:

• Letters (up to 3.5 inches long, 6.125 inches high, and 0.25 inches thick):
  • Up to 1 ounce: $0.55 (as of 2022)
  • 1 ounce to 2 ounces: $0.85 (as of 2022)
  • 2 ounces to 3.5 ounces: $1.15 (as of 2022)
• Large Envelopes (up to 12 inches long, 15 inches high, and 3/4 inch thick):
  • Up to 1 ounce: $1.00 (as of 2022)
  • 1 ounce to 2 ounces: $1.20 (as of 2022)
  • 2 ounces to 3.5 ounces: $1.40 (as of 2022)
• Flat Rate Envelopes (up to 13 inches long, 12 inches high, and 1/4 inch thick):
  • Small Flat Rate Envelope (up to 6-1/8 inches long and 3-5/8 inches high): $7.95 (as of 2022)
  • Medium Flat Rate Envelope (up to 11-1/2 inches long and 6-1/8 inches high): $13.95 (as of 2022)
  • Large Flat Rate Envelope (up to 12 inches long and 15 inches high): $19.95 (as of 2022)

Note that these rates apply to mailpieces that are not oversized or irregularly shaped. If your mailpiece is oversized or irregularly shaped, you may need to use a different type of mail service or pay a higher rate.

It's also worth noting that First Class Mail has a maximum weight limit of 13 ounces. If your mailpiece weighs more than 13 ounces, you will need to use a different type of mail service, such as Priority Mail.