How thick can first class mail be

According to the United States Postal Service (USPS), First-Class Mail has specific size and weight restrictions. Here are the details:

Size:

• Maximum length: 11.5 inches (29.2 cm)
• Maximum height: 6.125 inches (15.6 cm)
• Maximum thickness: 0.75 inches (1.9 cm)

Weight:

• Maximum weight: 3.5 ounces (99 grams)

Thickness exceptions:

• If your item is thicker than 0.75 inches (1.9 cm), you can still mail it as First-Class Mail, but you'll need to use a special envelope or package that's designed to withstand the rigors of mail handling. These envelopes or packages are typically made of sturdy materials, such as cardboard or thick paperboard, and are specifically designed for mailing items that are thicker than the standard 0.75 inches.

Examples of items that can be mailed as First-Class Mail:

• Letters, postcards, and greeting cards
• Small packages, such as those containing jewelry, coins, or small toys
• Books, magazines, and newspapers
• CDs, DVDs, and other small media items

Examples of items that cannot be mailed as First-Class Mail:

• Large packages, such as those containing clothing, electronics, or household items
• Items that exceed the maximum weight or size limits
• Items that require special handling, such as hazardous materials or perishable goods

If you're unsure whether your item can be mailed as First-Class Mail, you can always check with your local post office or the USPS website for more information.