USPS Shipping Calculator

Get the absolute best USPS Rates with Shippo. Calculate the savings using our USPS Shipping Calculator.

Access the Most Competitive USPS Shipping Rates

Shippo makes it easy for you to get the best possible shipping rates for your packages and print labels from the comforts of your fulfillment center—with no volume minimums or coding requirements.

Use our USPS shipping calculator to estimate your savings, then sign up for a free Shippo account to download your labels.

Compare Rates from Top Carriers

Take advantage of Shippo’s discounted rates for USPS, DHL Express, UPS, and others to save money. Shippo makes it easy to compare rates across carriers in real-time. 

You can also connect your own account to a global network of 85+ carriers, so you can leverage your own negotiated rates.

See our Global Carrier Network

Consider Popular USPS Shipping Service Levels

USPS Priority Mail is one of the most popular and cost-effective shipping options available for packages weighing over one pound. Options include:

Priority Mail: Weight-based. As the names imply, the shipping fees you pay are based upon the weight of the package and the distance it has to travel, which is also known as the “Zone.”

Priority Mail Flat Rate. “If it fits, it ships.” If your item fits within a specified Flat Rate box or envelope, it’ll ship for the pre-assigned rate of that package.

Priority Mail Cubic. Priority Mail Cubic is one of the best options available, since the USPS bases shipping prices on the size of the package and distance traveled, instead of the package’s weight.

Frequently Asked Questions

How do I calculate shipping costs?

Just enter your package details (dimensions, weight, origin, and destination zip codes) using the USPS shipping calculator displayed above to find the corresponding discounted rates from Shippo. Then, to purchase these rates, sign up for a free Shippo account.

How big of a box can I ship with USPS?

USPS Priority Mail allows you to ship items up to 70 pounds in box sizes up to 108 inches in total length and girth, which translates to the length of the longest side multiplied by 2, plus the width of the box multiplied by two.

What is the largest size box for Priority Mail?

If you’d like to use the free USPS shipping supplies, the largest branded USPS Priority Mail box available is the Priority Mail Large Flat Rate box which measures 12-1/4” (L) x 12-1/4” (W) x 8-1/2” (H) and can accommodate up to 70 pounds.

To ship larger items, you can use your own packaging and still utilize the service for boxes up to 108 inches in total length and girth.

Does the USPS charge by weight or size?

USPS shipping costs vary by service level. For USPS Priority Mail, for example, the cost is based on weight and distance traveled. There are a few exceptions.

First, USPS Priority Mail Cubic is one of the cheapest shipping options for packages smaller than a shoebox because the rates are determined by package size instead of weight.

For packages larger than 1 cubic foot in volume, the USPS also implements Dimensional Weight pricing, which takes size into account when determining the price.

And, with the USPS Priority Mail Flat Rate service, size and weight don’t matter as long as your item fits within the corresponding package.

How much does USPS shipping cost per pound?

USPS shipping costs are calculated based on weight and distance traveled. Packages weighing less than one pound start at $2.74 via USPS First Class Package Service.

If your package weighs one pound, you’ll want to use USPS Priority Mail which starts at $7.02 with Shippo’s special Cubic pricing. USPS accepts packages weighing up to 70 pounds.

What is the cheapest way to ship internationally?

The USPS is a cost-effective option for shipping internationally. There are a few great service levels to choose from: First Class Package International, for lightweight packages; Priority Mail International, for packages weighing more than one pound; and Priority Mail Express International, for packages that need to arrive quickly.

With Shippo, all you need to do is enter your package information and you’ll automatically see the cheapest way to ship it internationally within the drop-down menu.

*Rates are subject to change and do not include potential fees to use Shippo’s software (see pricing plans).

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