What is the weight limit for 1st class mail

The weight limit for First Class Mail in the United States is 13 ounces (369 grams). This is the maximum weight for a single piece of mail to be considered First Class Mail.

If a piece of mail weighs more than 13 ounces, it is considered a non-machinable package and must be sent as a Priority Mail or Parcel Post item. Non-machinable packages are subject to higher rates and may require additional handling and processing.

Here are some additional guidelines to keep in mind:

• First Class Mail letters and cards: 3.5 ounces (99 grams) or less
• First Class Mail flats: 13 ounces (369 grams) or less
• First Class Mail packages: 13 ounces (369 grams) or less
• Priority Mail: 70 pounds (31.8 kilograms) or less
• Parcel Post: 70 pounds (31.8 kilograms) or less

It's worth noting that the weight limit for First Class Mail is not the same as the size limit. Even if a piece of mail is within the weight limit, it must also fit within the size limits for First Class Mail, which are:

• Length: 11.5 inches (29.2 cm)
• Width: 6.125 inches (15.6 cm)
• Height: 6.125 inches (15.6 cm)

If a piece of mail exceeds these size limits, it may not be eligible for First Class Mail and may need to be sent as a Priority Mail or Parcel Post item.