Estimate common retail letter and postcard postage using rates effective July 12, 2026. This tool covers simple examples; unusual shapes, large envelopes, packages, destinations, and extra services need separate evaluation.

Current basics: 82¢ for a qualifying one-ounce stamped letter, 29¢ per additional ounce, 65¢ for an eligible domestic postcard, and $1.75 for the base international letter/postcard category.
Choose the mailpiece and weight.

How to get a useful estimate

  1. Assemble the entire mailpiece, including every insert.
  2. Weigh it accurately and round according to the applicable postal price step.
  3. Measure length, height, and thickness.
  4. Check whether it is square, rigid, uneven, or otherwise nonmachinable.
  5. Confirm domestic or international destination and any extra service.

Common stamp combinations

Qualifying letterPostageConvenient combination
Up to 1 oz82¢1 Forever
Up to 2 oz$1.111 Forever + 1 Additional Ounce
Up to 3 oz$1.401 Forever + 2 Additional Ounce
Up to 3.5 oz$1.691 Forever + 3 Additional Ounce

When not to use this simple calculator

Use a full USPS calculation or have the completed piece checked when it is a large envelope, package, square invitation, rigid card, lumpy envelope, international item above the base ounce, or mail with tracking, certification, insurance, or another service.

Frequently asked questions

Can I use two Forever Stamps for a two-ounce letter?

You can, but two current Forever Stamps total $1.64, which overpays the standard $1.11 two-ounce stamped-letter rate.

How many sheets of paper equal one ounce?

There is no guaranteed page count because paper, envelope, ink, cards, and inserts vary. Weigh the completed envelope.

Does the calculator cover nonmachinable mail?

No. Square, rigid, uneven, or unusually shaped pieces may need the nonmachinable surcharge.

Sources and update note

Reviewed August 2026. Verify current rates before mailing.

Package path: stamps or a shipping label?

For a package, first enter the exact packed weight, dimensions, destination and contents into the official USPS calculator. A label can combine postage, class, routing and tracking; loose stamps only show payment.

  1. Classify the completed item as a package, not a letter, when its shape and dimensions require it.
  2. Choose the service and added features before converting the dollar total into stamps.
  3. Apply enough valid postage without covering addresses, seams or label areas.
  4. A package over 10 ounces or more than one-half inch thick bearing only stamps must be presented at a Post Office retail counter under current Anonymous Mail rules; do not place it in an unattended collection box.

Insufficient postage can delay or return mail. If the calculator produces a label, use that label rather than translating it into an arbitrary number of Forever stamps.

USPS package-mailing guidance

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