Introduction
Use this free postage calculator to find out how much it costs to ship a letter, package, or parcel. Enter your package size, weight, and destination, and the tool shows you rates from USPS, UPS, FedEx, and DHL side by side. You can compare prices and delivery times in seconds so you pick the best option for your budget.
This shipping cost calculator works for domestic mail within the United States and international shipments to over 60 countries. It covers postcards, flat rate envelopes, flat rate boxes, and custom-sized packages. The tool also calculates dimensional weight, which carriers use to price large but lightweight boxes. Whether you are sending a small gift or a heavy box across the country, this calculator helps you find the cheapest way to ship it.
How to Use Our Postage Calculator
Enter your package details and shipping info below. The calculator will show you postage rates from USPS, UPS, FedEx, and DHL so you can pick the best price or fastest option.
Destination Country / Territory: Choose where you are sending your package. If you pick a country outside the United States, extra customs fields will appear.
Mailing From ZIP Code: Type the 5-digit ZIP code where your package starts its trip. This field only shows for domestic US shipments.
Mailing To ZIP Code: Type the 5-digit ZIP code where your package is going. This field only shows for domestic US shipments.
Shipping Date: Pick the date you plan to drop off your package. This helps estimate when it will arrive.
Shipping Time: Choose the time of day you plan to ship. This helps check if your package meets same-day cutoff times.
Declared Item Value: Enter the full dollar value of what is inside your package. Set this to $0.00 for letter-shaped mail.
Special Contents: Check any box that applies to what you are shipping. Options include cremated remains, live animals, day-old poultry, and hazardous materials. Each one limits which shipping services you can use.
Requires Ground Transportation Only: Check this box if your package cannot travel by air. This removes all air-only shipping options from your results.
Customs Items (International Only): For packages going outside the US, add each item with its description, value, quantity, weight, HS tariff number, country of origin, and category. Click "Add Another Item" to enter each one.
Mail Type: Pick the type of mail you are sending. Choose from Postcard, Flat Rate Envelopes, Flat Rate Boxes, or Shape and Size (Custom) for your own box or envelope.
Flat Rate Product: If you chose Flat Rate Envelopes or Flat Rate Boxes, pick the exact product from the dropdown. The price stays the same no matter how much your package weighs, up to 70 pounds.
Mail Shape: If you chose Shape and Size (Custom), pick the shape of your mail. Options are Letter, Large Envelope (Flat), Package, or Large Package. A large package is any box with a side longer than 12 inches.
Weight: Enter how much your package weighs. Use pounds and ounces in Standard mode, or switch to Metric to enter kilograms or grams. Weight is not needed for postcards.
Package Dimensions: Enter the length, width, and height of your package in inches or centimeters. These measurements are used to calculate dimensional weight, which carriers may charge instead of actual weight if your box is large but light.
Calculate Postage: Click this button to see all available shipping rates. Results show the price, carrier, delivery time, and included features for each service. Use the carrier tabs to filter by carrier and the sort menu to order by lowest price or fastest delivery.
Start Over / Reset: Click this button to clear all fields and return the calculator to its default settings.
How Postage Costs Are Calculated
Postage is the price you pay to mail a letter, envelope, or package through a shipping carrier like USPS, UPS, FedEx, or DHL. The cost depends on a few key things: how much your package weighs, how big it is, and how far it needs to travel.
Weight and Dimensional Weight
Carriers charge based on weight, but not always the weight you see on a scale. If your box is large but light, they may use something called dimensional weight instead. Dimensional weight is found by multiplying the length, width, and height of your box, then dividing by 166. The carrier picks whichever number is higher — the actual weight or the dimensional weight — and charges you for that one. This is why packing items in the smallest box possible can save you money. You can also use a CBM calculator to figure out the cubic volume of your shipment before packing.
Shipping Zones
A shipping zone is based on the distance between where you mail from and where the package is going. A short trip across town is Zone 1. A long trip across the country can be Zone 8. The higher the zone, the more you pay. For international mail, zones are set by the destination country.
Flat Rate Shipping
USPS offers flat rate envelopes and boxes. With flat rate, the price stays the same no matter how much the package weighs, as long as it fits inside the box and is under 70 pounds. This is a good deal for heavy items that fit in a small space.
Mail Types and Shapes
The shape of your mail changes the price. A postcard is the cheapest to send. A standard letter costs a bit more and is priced by the ounce. Large envelopes (also called flats) cost more than letters. Packages cost the most because they take up more room and are priced by weight and zone together. For larger commercial shipments, a freight class calculator can help determine your shipping classification.
Special Contents and Restrictions
Some items have special shipping rules. Hazardous materials and live animals cannot fly on planes and must go by ground. Cremated remains must be sent using Priority Mail Express. These rules limit which services you can use and may raise the cost.
International Shipping and Customs
When you ship to another country, you must fill out a customs form. This form lists what is in your package, how much each item is worth, and where it was made. International shipping costs more than domestic shipping because of the longer distance and extra handling at customs. Keep in mind that delivery estimates are measured in business days, so weekends and holidays are not counted. You can also use a lead time calculator to plan your supply chain and account for production and shipping delays together. If you are selling items online, remember to factor in marketplace fees using an eBay fee calculator or Etsy fee calculator alongside your shipping costs. Planning a household move instead? A moving cost calculator can help you budget for the full relocation.