Introduction
Our free USPS Shipping Calculator helps you find the cheapest way to send a package through the United States Postal Service. Just enter your ZIP codes, package weight, and box size, and the tool shows you estimated rates for every USPS service side by side. It works for domestic mail and for international shipping to the 39 countries USPS publishes a price group for. You can compare Priority Mail, Priority Mail Express, USPS Ground Advantage, Flat Rate envelopes and boxes, letters and postcards, all in one place, each at the price USPS publishes for your weight and zone.
The calculator also figures out dimensional weight, which is what USPS charges when a box is large but light. It picks the higher number between actual weight and dimensional weight so you see the real cost. The first $100 of coverage is included on Priority Mail, Priority Mail Express and USPS Ground Advantage; above that it adds USPS's published insurance fee for the value you declare. A bar chart and rate table make it simple to spot the best deal fast.
Whether you run a small business, sell items online, or just need to mail a gift, this tool saves you time and money. Enter your details below to get started.
How to Use Our USPS Shipping Calculator
Enter your package details below to get estimated USPS shipping rates, delivery times, and the cheapest mailing option.
Domestic or International: Click the "Domestic" tab to ship within the U.S. or the "International" tab to ship to another country.
Mailing From (ZIP Code): Type the 5-digit ZIP code where you are sending the package from.
Mailing To (ZIP Code) or Destination Country: For domestic shipments, type the 5-digit ZIP code you are shipping to. For international shipments, pick the destination country from the dropdown list.
Planned Mail Date: Pick the date you plan to drop off your package. This must be today or a future date.
Package Shape & Type: Select what you are sending. "Postcard" and "Letter" use First-Class Mail prices, "Flat Rate Envelope" and "Flat Rate Box" use USPS-produced Flat Rate packaging, and "Custom Package" prices your own box by weight and zone. If you pick a Flat Rate option, click the specific packaging you want.
Weight (lbs and oz): Enter your package weight in pounds and ounces. Ounces must be between 0 and 15.9. Letters are priced by the ounce, so the ounces field matters most there.
Length, Width, and Height (in): Enter your package dimensions in inches. These fields only show for custom packages. The calculator uses these to find the dimensional weight and compare it to the actual weight.
Declared Item Value ($): Enter what the contents are worth. Priority Mail, Priority Mail Express and USPS Ground Advantage include the first $100 of coverage, so nothing is added below that.3 Above it, the calculator adds the insurance fee USPS publishes for that amount of coverage. The box is hidden for postcards and letters.
Calculate Button: Click "Calculate" to see your estimated USPS shipping rates. The tool shows the cheapest option, a full rate table, and a bar chart comparing all available services.
Reset Button: Click "Reset" to clear all fields and start over with the default values.
How USPS Shipping Costs Work
USPS (United States Postal Service) is the main mail service in the United States. It delivers letters, packages, and boxes to every address in the country and to most countries around the world. Millions of people and businesses use USPS every day because it is often the cheapest way to ship.
The price you pay to ship something with USPS depends on a few key things. Weight is the most important factor, since heavier packages cost more to send. Distance also matters. USPS splits the country into shipping zones numbered 1 through 9, and publishes a zone chart for every origin ZIP code.1 Zone 1 means the destination is close to you, and the higher zones are farther away. A higher zone means a higher price.
Package size can also change your cost. USPS uses something called dimensional weight (or DIM weight). If your box is large but light, USPS may charge you based on the size of the box instead of how much it actually weighs. They pick whichever number is bigger: the real weight or the DIM weight. USPS rounds each side up to a whole inch before it multiplies them, and if the dimensional weight exceeds 70 pounds, the customer pays the 70-pound price.2 USPS also adds nonstandard fees for a package longer than 22 inches or larger than 2 cubic feet.1
USPS offers several service levels. USPS Ground Advantage is the most affordable and takes 2 to 5 business days. Priority Mail is faster, usually 1 to 3 days. Priority Mail Express is the fastest option, arriving in 1 to 2 days. For items that weigh very little, First-Class Mail is the cheapest choice. If you are managing supply chain timelines, our Lead Time Calculator can help you plan when to place orders so shipments arrive on schedule.
If you do not want to weigh or measure your package, USPS also sells Flat Rate envelopes and boxes. With Flat Rate, the price stays the same no matter how much your item weighs or how far it goes, as long as it fits inside the envelope or box and meets the weight limit of 70 pounds.2
For international shipping, USPS sorts destination countries into published price groups, and the group decides the price rather than the distance.1 Each service has its own groups, so Ireland is in group 4 for Priority Mail International and group 9 for First-Class Package International Service.1 This calculator prices the 39 countries whose groups are published in the price list, and each country also has its own maximum weight, which can differ between services. A destination or weight USPS does not publish a price for is listed as not priced, with the reason, rather than estimated. Priority Mail International is charged by weight and price group, so the size of the box does not change its price.4 Letters, large envelopes and postcards go by First-Class Mail International, and a letter over 3.5 ounces is charged the large envelope price.5
If the item you are shipping is worth a lot of money, you can add insurance by declaring its value. USPS includes free coverage up to $100 on most services.3 Above that amount, there is a small extra fee to protect your package in case it gets lost or damaged.