Introduction
The Postage Calculator shows what the United States Postal Service charges to mail a postcard, a letter, a large envelope or a package, using the retail prices in USPS's price list, Notice 123. Choose where the item is going and what you are mailing, enter its weight, and the calculator shows the published price of every USPS service that can carry it.
It covers mail within the United States and mail to other countries. Postcards, letters and large envelopes go by First-Class Mail. Packages go by USPS Ground Advantage, Priority Mail or Priority Mail Express within the country, and by First-Class Package International Service, Priority Mail International or Priority Mail Express International abroad. Flat Rate envelopes and boxes are included for mail within the United States.
To compare UPS, FedEx and DHL for the same package, use our Shipping Calculator, and for every USPS package option with delivery dates, our USPS Shipping Calculator.
How to Use Our Postage Calculator
Where Is It Going? Choose Within the U.S. or To Another Country. For a package within the United States, enter the ZIP code you are mailing from and the one it is going to. For another country, pick it from the list.
What Are You Mailing? Choose Postcard, Letter, Large Envelope, Package or Flat Rate. Tick Nonmachinable letter if your letter is square, rigid or lumpy, or closes with a clasp or string. For Flat Rate, pick the envelope or box.
Weight: Enter the weight in pounds and ounces, or switch to Metric and enter grams or kilograms. A postcard needs no weight.
Package Size: For a package, enter the length, width and height in inches or centimeters. Tick the box below them if the package is a tube or roll, a can, a wooden or metal box, or holds liquids.
Insurance: For a package or a Flat Rate item, enter what the contents are worth to add USPS's insurance fee.
Click Calculate Postage to see each price with its delivery time in business days, a price chart and a step-by-step breakdown, or Reset to start again.
How Postage Is Worked Out
Postcards, Letters and Large Envelopes
Within the United States, a stamped postcard costs $0.65 and a stamped letter up to 1 oz costs $0.82.1 Letters are priced by the ounce up to 3.5 oz, and a heavier letter pays the large envelope price.1 Large envelopes, also called flats, are priced by the ounce up to 13 oz, starting at $1.69.1 A nonmachinable letter pays an extra $0.49.1
A letter is nonmachinable if, for example, its length divided by its height is less than 1.3 or more than 2.5, it is too rigid to bend, it has clasps, strings or buttons, or it holds pens, keys or coins that make it uneven.2
A letter can be up to 11-1/2 inches long, 6-1/8 inches high and 1/4 inch thick.1 A large envelope is bigger than that in at least one way, up to 15 inches long, 12 inches high and 3/4 inch thick.1 Pieces that are rigid, nonrectangular, or not uniformly thick pay parcel prices.1
Packages Within the United States
USPS prices a package by its weight and its zone, and zones are numbered 1 to 9.1 The calculator finds the zone in USPS's zone chart for the ZIP code the package is mailed from.
A large, light box can be charged by its size instead, called dimensional weight. USPS rounds each side up to a whole inch and multiplies them; if the result exceeds 1,728 cubic inches, it divides by 139 and rounds up.3 The package is charged on whichever is higher, that or its actual weight, and if the dimensional weight exceeds 70 pounds, the customer pays the 70-pound price.3
USPS adds nonstandard fees for long, large or awkward packages. For USPS Ground Advantage, it adds $4.50 for a package longer than 22 inches, $10.00 if it is longer than 30 inches, and $21.00 if it is larger than 2 cubic feet.1 For Priority Mail and Priority Mail Express the same fees are $4.50, $21.00 and $35.00.1 Tubes, rolls, cans, wooden or metal boxes and some containers of liquid add $4.50.1 A piece that is subject to both a length and a characteristics fee is only subject to the highest fee, but the size fee can be added to either.3 Flat Rate packaging is exempt from these fees on Priority Mail.3
No mailpiece may measure more than 108 inches in length and girth combined, except USPS Ground Advantage, which allows 130 inches, and no mailpiece may weigh more than 70 pounds.2 A Ground Advantage package measuring more than 108 inches but not more than 130 inches pays the oversized price for its zone, whatever it weighs.1
Flat Rate
Flat Rate envelopes and boxes cost the same regardless of the domestic destination or actual weight, up to 70 pounds.3 A Small Flat Rate Box costs $13.65 by Priority Mail.1
Mail to Other Countries
USPS puts each country in a price group, and each service has its own groups. Ireland, for example, is in group 4 for Priority Mail International, group 9 for First-Class Package International Service and group 5 for First-Class Mail International.1
Priority Mail International is charged for each piece according to its weight and price group, so the size of the box does not change its price.6
A postcard to another country costs $1.75, and so does a letter up to 1 oz.1 A letter over 3.5 ounces is charged the First-Class Mail International large envelope price, and a large envelope can weigh up to 15.994 ounces.5
Puerto Rico, Guam and the U.S. Virgin Islands are domestic mail, so choose Within the U.S. for them.7
Insurance
Priority Mail Express, Priority Mail and USPS Ground Advantage include $100.00 of insurance coverage.4 Above that, USPS charges a fee by the value covered, such as $4.55 for $200.01 to $300.00 and $9.05 plus $1.50 for each $100.00 over $600.00.1 For Priority Mail International and Priority Mail Express International there is no fee for coverage up to $200.00.1