Use this calculator for ordinary stamped domestic letters, domestic postcards, and qualifying one-ounce international letters or postcards. It uses USPS retail prices effective July 12, 2026. It does not price packages, flats, certified mail, or international pieces over one ounce.
Select the finished mailpiece details, then calculate.
Rates used by the calculator
| Mailpiece | Retail amount |
|---|---|
| Domestic stamped letter, up to 1 oz | $0.82 |
| Each additional ounce or fraction for an eligible letter | $0.29 |
| Nonmachinable letter surcharge | $0.49 |
| Domestic postcard | $0.65 |
| Qualifying international letter or postcard, up to 1 oz | $1.75 |
Why the result can change at the Post Office
Weight is only one part of postage. A square invitation, rigid card, clasp, wax seal, uneven insert, large envelope, or piece outside letter dimensions can change the classification. International prices above one ounce also depend on destination and mailpiece type. For those cases, use the official USPS postage calculator or show the assembled piece to USPS.
Use the result with the right guide
- How many Forever Stamps do I need?
- What one Forever Stamp covers
- Postcard stamps versus regular Forever Stamps
- Wedding invitation postage
- Global Forever Stamps
Rates reviewed August 12, 2026 against USPS Notice 123. This is an independent educational estimate, not a USPS acceptance decision.