Jun 2, 2022 9:15:00 AM | Payment & Shipping A Quick Guide to Ship Fast and Save Money with USPS

Learn the basics of USPS, including what Click and Ship is and some practical advice on shipping your package.

Table of Content

  1. Intro
  2. Package Size and Weight
  3. Mail service options in USPS
  4. What is Click and Ship USPS
  5. How to ship a package
  6. Things you can’t mail
  7. Tips on international shipping



United States Postal Service (USPS) is the most extensive postal system globally, delivering 47% of the mail in the world. It has provided postal service for more than 240 years in the United States. Since fulfillment is an essential part of e-commerce operations, knowing how to utilize USPS resources and services is vital for online business entrepreneurs to ship packages and save money.

This post will cover the basics you need to know about USPS and provide some tips you can use when packaging and shipping your items.


Package size and weight

To begin with, let's look at how USPS measures the dimensions and weight of a package, as these factors are directly related to shipping costs. Measuring every inch and ounce precisely can help ensure you get the best price for your USPS parcel deliveries.

Measure dimensions

Dimension consists of length, width, and height. Depending on what you are shipping, packages can come in different shapes and sizes. For rectangular parcels, it's easier to measure the exterior dimensions with sewing or measuring tape. To find the volume of the package in cubic inches, multiply the length, width, and height together. For non-rectangular parcels, if you want to mail a guitar or a tire, apply the same formula but use the result to multiply 0.785 to calculate the volume. For tubes, use the diameter of the circular base as width and height and the longest side as length.

Non-rectangular parcels


Measure weight

When it comes to weight, keep in mind that the USPS has been employing a pricing concept known as dimensional weight, or dim weight, to determine shipping rates by considering both the weight and the size of an item. Because it would be unreasonable to charge more to ship a large box of feathers than a little box of pebbles, USPS used the dim weight to compare against the actual weight of a parcel. The greater value is used for shipping cost adjustments. Anything larger than one cubic foot -- or 1,728 cubic inches -- will require a dim weight calculation.

To find dimensional weight, or dim weight, measured in pounds, take your volume (length times width times height) and divide by 166. For example, if your package is 16 inches long, 14 inches wide, and 14 inches tall, its volume will be 16*14*14, or 3,136 cubic inches. Divided by 166, the dimensional weight is around 19 pounds.

With your measurements, you can now use the postage price calculator on the USPS.com website to estimate the cost of your shipment.

USPS postage price calculator


Mail service options in USPS

When choosing a shipping service, there are several things to consider, including package contents, destination, speed, dimension, and special handling and insurance. USPS has a variety of mail services, including Priority Mail Express®, Priority Mail®, First-Class Package Service-Retail™, USPS Retail Ground®, and Media Mail®.

You can compare these services by starting price, different delivery speeds, package sizes, and extras like tracking and insurance. For instance, Priority Mail Express is the fastest domestic shipping service in the United States. It has the following features:

  1. Next-day delivery is available to most U.S. addresses and PO Boxes with a money-back guarantee.
  2. It provides USPS tracking and proof of delivery signature record.
  3. This service is excellent for shipping boxed jewelry, clothing, or valuable and time-sensitive items.

By comparison, USPS Retail Ground® is a reliable and economical way to ship less-than-urgent deliveries and oversized packages. It is suitable for too large packages for Priority Mail Express and Priority Mail delivery.


What is Click and Ship USPS

Click-N-Ship is a service offered by USPS that allows customers to create and print legitimate USPS shipping labels online for various mailing services. With the Click-N-Ship service, you can:
• Purchase prepaid labels online
• Pay for postage with any major credit card
• Calculate and compare rates
• Standardize your addresses
• Find a ZIP Code

The Click and Ship service itself is free of charge itself. Additionally, customers end up saving money between postage paid for at the post office and the postage paid through the Click and Ship program. Although the amount is not a lot, if you are sending many packages, all of those pennies will add up over time.


How to ship a package

Now we know how to measure the dimensions and weight and choose from different mail services. Next, we have prepared a guide on how to ship your package.

Step 1: Pick a box with a right size

Make sure the box is big enough to fit what you're sending safely. Try to stick to standard sizes and avoid paying fees for nonmachinable packages. Remember that the size and shape of the box will impact your earnings.

Step 2: Wrap a box properly

Pack your box to protect your contents, and make sure the package arrives intact. Tape your parcel to close the flap on all sides without bulging, and reinforce the flaps with 2-inch-wide packing tape.

Step 3: Choose a mail service

The best way to send your package depends on how quickly you want it to arrive and its size and weight. USPS has a variety of mail services, different delivery speeds, package sizes, and extras like tracking and insurance.

Step 4: Calculate and apply postage

You can enter your package information into the USPS Postage Calculator to get postage prices for different services. You can pay for your postage at a Post Office location or use the Click-N-Ship service to create a prepaid shipping label with some discounts. Also make sure you choose the appropriate service.

Step 5: Ship your items

Where to mail your box depends on its size and where you live. You can visit a Post Office location, request free package pickups, or leave your parcel with an Approved Postal Provider.


Things you can’t mail

There are several items you are not allowed to mail, including hazardous materials, restricted matter, and perishable matter. Anything explosive, toxic, and capable of posing a risk to health, safety, and property during the transportation is considered hazardous and unacceptable by USPS. Nor are you allowed to mail items prohibited or limited by title 18 of the U.S. code, like drugs, firearms, knives, and sharp instruments. Other things that require special permits include cigarettes, prescription medications, perishable food, nail polish, and glue. So, if you are still struggling with what to sell for your online business, being aware of these mail restrictions could be critical to avoiding some potential pitfalls.


Tips on international shipping

Cross-border e-commerce has become increasingly popular in the past years. If you are selling globally, you will need this guide on how to send international packages with USPS.

1. Check this International Shipping restriction for general guidance before sending packages to your destination country. You can find out items you are not allowed to send and items you can send under certain conditions.

2.Choose the international shipping service that works best for you based on price, speed, and available features.

Compare International Mail Services

3. Pack your box with extreme care to protect your contents and ensure the package arrives intact. Since international shipments are usually transferred several times among different shipping modes, confirm that the item has sufficient cushioning and reinforcing material to prevent loss or damage. You can use polystyrene foam peanuts, bubble wrap, cloth, or newspapers to help fill empty spaces and curb movement.

4. Write the address correct International address formats are different for each country, so get specific information about other countries’ postal addresses to avoid any mistakes. One tip is to include the recipient’s full name and address on a piece of paper and put it inside your package.

5. It's requested that you create customs forms when you send packages to other countries. If you use the Click-N-Ship service to print your postage, it will print a customs form for you. However, if you'll be paying for your postage at the Post Office, you need to fill out Form PS 2976-R and give it to the USPS retail associate so they can create and print your customs form. So to save time, you'd better print your own customs forms at home using online tools.



In this post, we have covered the basics of USPS and some shipping and packaging tips for merchants who need to manage their delivery. We will discuss how USPS helps small businesses ship and save in the next posting. Stay tuned!

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Written By: Min Chen

Read articles written by Min Chen and learn the essentials about developing eCommerce businesses on Shoplazza.