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USPS Postage Calculator & Mailing Cost Estimator

Estimate postage costs for domestic and international mail. Compare USPS rates for letters, large envelopes, flats, and packages.

Round up to the next ounce; USPS charges by rounded weight.

For a standard #10 envelope, choose 'Letter'.

How this postage calculator works

We built this tool so our users have a quick way to look up postage costs from USPS. It returns live quotes similar to what you would get at the post office. You can then decide whether you would like to use our service or take the time to drive to the post office.

You can look up different types of mail service as well as international mail. This is an estimate of what you will pay when mailing directly through the post office, so keep that in mind when making your decision.