How the USPS prices are built
Every price on this site is a cell of a Postal Service price file, read on November 13, 2026, chosen by the service, the weight step and the zone; the zone is read in the official zone chart from the first three digits of the two ZIP Codes. Nothing is estimated. For January 17, 2027, the proposed base price is multiplied by 1.11 for the fuel surcharge and rounded to the cent.
The Postal Service publishes its prices as a spreadsheet of several dozen sheets and its zones as a chart per ZIP Code prefix; carrier calculators ask you to sign in, and price pages online quote last year or forget the fuel surcharge. This site reads both files and answers in one screen: what a package of this weight costs from your ZIP Code to theirs, at the Post Office and with an online label, today and from January 17, 2027, with the proposed 11% fuel surcharge counted.
1. The price files
The Postal Service publishes each price change on Postal Explorer as a Notice 123 workbook. Three of them were downloaded and read sheet by sheet: retail and commercial Priority Mail, Priority Mail Express and Ground Advantage, Media Mail, First-Class Mail and the domestic extra services.
| Prices | File | Period |
|---|---|---|
| July 2026 | July 2026 Price Change - 07082026 - Notice 123.xlsx | July 12, 2026 to October 3, 2026 |
| Today (time-limited) | Time-Limited OCT 2026 Price Change - Notice 123 - Final.xlsx | October 4, 2026 to January 16, 2027 |
| January 2027 (proposed) | January 2027 Price Change - 11122026 - Notice 123.xlsx | from January 17, 2027, plus 11% fuel surcharge |
2. The zone
The Domestic Zone Chart of the Postal Service gives, for each 3-digit origin prefix, the zone of every destination prefix, with a legend: an asterisk for a destination in the same network distribution center, a plus sign for ranges with 5-digit exceptions. The chart of all 914 origin prefixes it serves, effective November 1, 2026, was read on November 13, 2026 and stored as served; the 5-digit exceptions are applied by service. The chart is not fully symmetric: the zone from A to B equals the zone from B to A in 99.8% of pairs.
3. Weight steps and size weight
From the Domestic Mail Manual: Ground Advantage under 1 pound is charged at 4, 8, 12 and 15.999 ounces, then by the pound to 70 pounds (DMM 133); Priority Mail at a counter by the pound, any fraction a full pound (DMM 123), with a half-pound step online; Priority Mail Express from a half pound (DMM 113); Media Mail by the pound (DMM 173). Above 1,728 cubic inches, each side rounded up to the inch, the size weight is length times width times height divided by 139, rounded up, and the higher of size weight and real weight is charged, never above the 70-pound price. Length fees above 22 and 30 inches, the volume fee above two cubic feet and the Ground Advantage oversized price between 108 and 130 inches come from the footnotes of Notice 123; limits from DMM 201.
4. The January 2027 prices
The release of November 12, 2026 announces an 11% fuel surcharge on Priority Mail Express, Priority Mail, Ground Advantage and Parcel Select, replacing the time-limited 8% of the March 25, 2026 release. The January 2027 workbook gives base prices and two surcharge sheets at 0.11. The site applies 1.11 to the shipping services and their flat rate packaging, not to letters, Media Mail or extra services. The filing, docket CP2027-1, is under review at the Postal Regulatory Commission: these prices are proposed.
5. A worked example
An 18 by 14 by 12 inch box of 5 pounds from New York (10001) to Los Angeles (90012). Zone chart: zone 8. Volume 3,024 cubic inches, over one cubic foot: size weight 3,024 ÷ 139 = 21.8, rounded up to 22 pounds, higher than 5. Priority Mail at a counter, 22 pounds, zone 8: $122.15; the box is under 22 inches long, so no length fee. From January 17, 2027: base $112.25 plus $12.35 of fuel surcharge, $124.60.
6. Limits
- UPS, FedEx and other carriers are not covered: their price lists refused automated reading, and no figure was copied from elsewhere.
- Business Rate Card, Priority Mail Cubic, Parcel Select, Ground Advantage Limited Overland Routes inside Alaska, international mail and hazardous material fees are left out.
- Sunday and holiday delivery premiums, pickup and packaging costs are not added.
- The Postal Service may round the surcharge differently at checkout; the price it shows is the one you pay.
- Nothing updates by itself: the date of the files is shown on every page.
Corrections: contact page.