USPS Shipping Calculator
Get up to 89% off USPS shipping rates with Descartes ShipRush.
USPS Discount Shipping Services
Shipping rates depend on the destination, size, weight, and desired service for each package.
USPS Priority Mail
- Best for U.S. domestic shipments
- Delivery typically takes 1-3 business days
- Ship parcels up to 70 pounds
- Package length + girth cannot exceed 108 inches
USPS Priority Mail Cubic Discounts
- Special rates for small, heavy parcels
- Think “shipping a brick” – Learn More
- Typically delivered in 1-3 business days
- Up to 0.50 cubic feet (or 36” poly bag) and less than 20 pounds
USPS Priority Mail Express
- Faster U.S. domestic shipments
- Usually delivered in 1-2 business days
- Same package size and weight criteria as Priority Mail
USPS Ground Advantage
- Best for non-urgent U.S. domestic shipments
- Budget-friendly ground-only shipping option
- Expected delivery in 2-5 business days
- Up to 70 lbs. and up to 130 inches combined package length + girth
USPS Ground Advantage Cubic Discounts
- Special rates for small, heavy, non-urgent shipments
- Cheapest, slowest USPS shipping service
- Typically delivered in 2-5 business days
- Parcels up to 1 cubic foot and up to 20 pounds
Beyond the Cheapest Shipping Rates
Save money with multi-carrier rate comparison
Gain efficiencies with shipping automation
Eliminate mis-ships with sales channel integrations
Access free live customer support via chat, phone, and email
USPS Shipping FAQs
How do you calculate USPS shipping?
- First, decide what type of packaging to use and completely package your item.
- Measure your sealed package’s length, width, and height in inches.
- Then, use a scale to weigh your package in pounds and ounces.
- Enter the package origin and destination Zip Codes in the shipping calculator “To” and “From” fields
- Select your packaging type and enter the dimensions and weight based on your measurements
- Click “See Shipping Rates”
- Descartes ShipRush uses the information you entered to find the correct zone and USPS shipping rates based on USPS partner rate cards.
- The shipping software automatically applies our USPS partner discount and displays the discounted rates for all available shipping services.
Note: This Descartes ShipRush rate calculator estimates shipping rates based on our pre-negotiated partner rates. Estimates will not include any rates you have negotiated directly with a carrier. To see a side-by-side rate comparison of your own carrier rates vs. our discounted rates, please create a Descartes ShipRush account and try it free for 15 days.
Does USPS charge by size or by weight?
Both size and weight factor into USPS parcel shipping rates, and smart shippers use this to their advantage. For example, you can ship a package with up to 108 inches of combined length (longest side) + girth (measured as distance around thickest part of the non-length sides) with USPS Priority Mail. You can ship a larger package up to 130 inches of combined length + girth with USPS Ground Advantage, but you will be charged at the oversized price1. A few slight adjustments to package size can end up saving you a lot of money.
Similarly, you can access cheaper USPS shipping services for a heavy parcel (up to 20 pounds) with small package dimensions around the size of a shoebox. USPS Priority Mail Cubic rates are based on a parcel size with a maximum length of 18” and cubic volume of up to 0.50 cubic feet2. Package heavy items in as small a box as possible and use USPS cubic rates to reduce shipping costs.
How big of a package can I ship with USPS?
A USPS parcel can weigh up to 70 pounds with a maximum package size of 130 inches in combined length + girth. It’s important to note that packages between 108-130 inches in combined length + girth do incur oversized pricing fees and ship via the slowest shipping service (USPS Ground Advantage)1.
