Weight-Based Priority Mail
Pirate Ship automatically rate shops between Weight-based Priority Mail and Priority Mail Cubic to optimize your savings. You can get incredible shipping rates with weight-based Priority Mail... just watch out for Dimensional Weight pricing if your box is large!
Max Length + Girth: 108" inches
Max Weight: 70 pounds
Part of a best-rates mix with Priority Mail Cubic
Combining Weight-Based Priority Mail with dimension-based Priority Mail Cubic maximizes savings.
Delivery in 1 to 3 business days
USPS® delivers Priority Mail packages to anywhere in the USA and its territories within 1 to 3 days.
Free package tracking included
Priority Mail shipments include full tracking from door-to-door, so you'll always know where your shipments are.
$100 insurance included for free
Priority Mail Cubic postage purchased from Pirate Ship includes $100 of USPS liability insurance for free.
Save up to 47% by using Pirate Ship
Pirate Ship's BELOW Commercial Pricing® rates for Priority Mail will save you up to 47% compared to retail prices.
Get Priority Mail rates that are cheaper than Commercial Pricing
Unlike other places to buy USPS postage online, Pirate Ship offers BELOW Commercial Pricing rates for Priority Mail for shipments to and from the lower 48 states, with absolutely no markup, fees, or monthly costs. So you get the deepest discounts available for free, with no risks or commitments.
Packages exceeding 1 cubic foot are charged the dimensional weight (Length x Width x Height / 166) if greater than the actual weight.
Only for shipments to/from the lower 48 states. Create a free account & get a rate quote to see the rates.
For large but light packages, watch out for Priority Mail dimensional weight pricing
Dimensional weight is common for every carrier, basically because they don't want to fill up their trucks and planes with packages that are large but mostly empty & light.
If your package is larger than 1 cubic foot (for example, if the dimensions are 13" x 13" x 13") then USPS uses a formula to calculate the minimum rate they will charge. It's based off the dimensions, which is why this is known as the "dimensional weight" or "DIM weight". If your package's dimensional weight is "heavier" than the actual weight, you will be charged as if your package were that heavier weight.
Dimensional weight is calculated by multiplying a package's length, width, and height and then dividing by the volumetric divisor. USPS uses 166 for their divisor.
So for an example of a package that measures 13" x 13" x 13", you would multiply the three dimensions to get 2197, and then divide that by 166 to get 13.23, which is the dimensional weight. So if your package's actual weight was less than 13.23 pounds, you would get charged the 14 pound Priority Mail rate. If your package was more than 13.23 pounds, the dimensional weight would be disregarded and you would just be charged the actual weight.