Postage / Stamp Calculator

USPS postage rates (2025) for letters and packages:

First-Class Letters (domestic):

• 1 oz or less: $0.73 (1 Forever stamp)
• Each additional ounce: +$0.28
• Maximum weight: 3.5 oz

Postcards: $0.56 each

Large Envelopes (Flats):

• 1 oz: $1.35
• Each additional ounce: +$0.28
• Maximum weight: 13 oz

International First-Class Letters:

• 1 oz Global Forever stamp: $1.65
• Each additional ounce: varies by destination

Tips:

• Forever stamps retain their value even if rates increase
• Use online postage (USPS.com, Stamps.com) for possible discounts
• Oversized, rigid, or non-machinable letters require extra postage ($0.46 surcharge)
• Weight includes envelope and contents

Note: Rates are approximate and subject to USPS rate changes.