How to Calculate First-Class Mail Postage
- 1). Go to the US Postal Service website link in the Resources section.
- 2). Select the appropriate destination in the "Select a Destination" drop-down menu. For example, if you are mailing a package within the United States, select "United States (Domestic Mail)".
- 3). Choose the type of contents you are mailing from the following options: Postcard, Letter, Large Envelope or Package.
- 4). Enter the weight in pounds and ounces.
- 5). Enter the "From" and "To" Zip codes for mail that will be sent within the United States.
- 6). Select the appropriate shipping date and time. Click on the "Continue" button.
- 7). Look up the price for "First-Class Mail" under the "Post Office Price" column.
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