Finding the cheapest USPS shipping rates and knowing when to use USPS or another carrier helps ensure that you are saving as much money as possible on your shipping costs. ShipStation and Stamps.com help ensure that you never pay any more for shipping than you have to. With savings of up to 87% on USPS First Class, Priority, Media Mail, and Cubic services, you can always find affordable shipping rates.

Shop USPS Shipping Rates via your ShipStation Account

Finding the right shipping service can be complicated. But, if you’re using the USPS, the options may be a little simpler. Parcel services from the USPS are pretty straightforward. The different services ultimately cater to specific needs. ShipStation’s USPS Shipping Calculator lets you compare all available rates for USPS orders. If you are using ShipStation, or would like to, we also offer an in-app rate calculator that lets you compare rates from all carriers. ShipStation also offers 

How Does USPS Calculate Shipping Costs? 

The USPS uses a few factors to calculate shipping rates. While other carriers like UPS and FedEx have surcharges that fluctuate depending on the recipient’s address and other factors, the USPS doesn’t usually add surcharges beyond the base rates they quote. This is due in part to the USPS charging label fees upon creation rather than postbilling. The other reason that the USPS has more stable pricing is that they are obligated to deliver to any and all US addresses. 

How Package Weight Determines USPS Rates

USPS uses package weight to determine the base shipping rate. This is true of most other carriers as well. If the weight increases to the next pound, the rate will rise. The maximum package weight for USPS is 70 lbs. If you exceed the weight limit, the USPS will apply a $100 surcharge to your total. This fee must be paid by you or the recipient in order to make final delivery.

How Destination and Shipping Zones Impact USPS Rates

USPS zones adjust the base rate applied to domestic parcels. The higher the zone, the higher the rate. Depending on the weight or the zone, other carriers such as UPS may have lower rates—particularly for shipments weighing more than about 6 lbs. A common way merchants decide the cheapest way to ship is to automatically apply the shipping service based on destination zip code. It’s just as effective—and far simpler—to use zones to determine the cheapest shipping service. 

How Package Dimensions Determine USPS Shipping Rates

Dimensions can play a big part in shipping costs. Typically, they work as a maximum threshold for a parcel’s size. However, smaller packages can cost substantially less than larger ones and have cubic pricing apply. To learn more about USPS Cubic rates, check out the current USPS rates available in ShipStation.

How Surcharges Impact USPS Shipping Rates

Luckily, the USPS doesn’t have as many surcharges as other carriers. Typically, the only USPS surcharges come in the form of peak surcharges. These usually come into effect during the holiday season. But it is possible that other peak season surcharges will apply due to the recent boom in ecommerce. While carriers like FedEx and UPS have residential surcharges that can increase the shipping rate by about $4.00, the USPS offers the same rate structure to all addresses.

When a USPS Service Is Cheapest

ShipStation offers a wide array of USPS services that work best for different parcels with specific needs. We even offer discounts of up to 87% off retail rates! To see if your packages’ weight and dimensions fit the criteria for each service, read our USPS overview. 

USPS First-Class Mail®

Parcels under 16 oz. are almost always going to be cheapest with USPS First Class Mail. For domestic packages, the service offers tracking and usually takes no more than one more day to deliver than USPS Priority Mail. 

USPS Media Mail®

USPS Media Mail is a service that is a bit slower than First Class Mail. But if you are shipping DVDs, books, CDs, magazines, vinyl records, or similar items weighing less than 70 lbs, you won’t find a cheaper option. Keep in mind that one thing that makes USPS Media Mail is that your parcels may be inspected to verify approved content. 

USPS Ground Advantage™ 

USPS Ground Advantage is the most economical way to ship domestic parcels up to 70 lbs. It replaced Parcel Select Ground, Retail Ground, and First-Class Package Service to simplify ground shipping. Delivery typically takes 2–5 business days and includes tracking and $100 of insurance at no extra cost.

USPS Priority Mail®

USPS Priority Mail is one of the cheapest for domestic parcels weighing between 1-7 lbs. Once parcels reach this weight, especially for further destination zones, UPS Ground/Home® becomes a more affordable option. This is particularly true of discounted UPS rates available through ShipStation. 

USPS First-Class Mail International®

USPS First Class Mail International is usually the most affordable way to ship a parcel internationally that weighs less than 4.4 lbs. However, the service can take a long time to reach its final destination. 

USPS Priority Mail International®

USPS Priority Mail International is usually the most affordable option for lightweight parcels that need to be expedited more quickly. Most international markets that the US frequently ships to can make final delivery in 6-10 days. 

Get a USPS Shipping Quote with ShipStation

USPS is one of the world’s most well-reviewed national postal provider. Their commitment to delivering to every US address makes them a great choice for domestic shipping. And occasionally, they offer competitive international rates. ShipStation lets you compare these rates as well as the rates from many other carriers—many of whom offer discounted shipping rates. Having a way to compare rates between multiple carriers lets you ensure that you are using the best shipping service every time. 

To start saving on USPS label fees and any other shipping provider you may use, tryShipStation free for 30 days. 

James Messer
James Messer

James Messer is a copywriter specializing in shipping, logistics, and ecommerce.

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