How much is an additional ounce for first class mail

According to the United States Postal Service (USPS), the cost of an additional ounce for First Class Mail is $0.21 as of January 2022.

Here's a breakdown of the First Class Mail rates:

• 1 oz: $0.55
• 2 oz: $0.65 (additional ounce: $0.10)
• 3 oz: $0.75 (additional ounce: $0.20)
• 4 oz: $0.85 (additional ounce: $0.30)
• 5 oz: $0.95 (additional ounce: $0.40)
• 6 oz: $1.05 (additional ounce: $0.50)
• 7 oz: $1.15 (additional ounce: $0.60)
• 8 oz: $1.25 (additional ounce: $0.70)
• 9 oz: $1.35 (additional ounce: $0.80)
• 10 oz: $1.45 (additional ounce: $1.00)

Please note that these rates are subject to change, so it's always a good idea to check the USPS website for the most up-to-date information.