
You don’t even have to worry about how far this package is traveling to figure out how much it’s going to cost, either. All you have to do is get your hands on a USPS large flat rate shipping box, fill it up, seal it up, address it correctly, pay the flat rate shipping fee and you are good to go. It really doesn’t get much easier than that! There’s no more measuring box size or slipping it on a scale before calculating postage. There’s no more need for trying to track down the right box. To kick things off, a big piece of the puzzle behind the popularity of the USPS Flat Rate service is how economical it is. Probably the cheapest way to send heavy items through the mail (with the USPS or anybody else, for that matter), flat rate shipping eliminates the need to weigh items, to worry about dimensionality, or to measure delivery distance. It’s possible to save a lot of money on shipping, particularly high-volume shipping of heavier items.Īnother reason that USPS Flat Rate shipping is so popular is because it is so easy! The whole process is simplified dramatically compared to “traditional” shipping options. It continues to be one of the most often utilized delivery solutions, especially for e-commerce operations and small businesses that don’t want to spend a small fortune on shipping.īelow we run through some of the biggest benefits of this program, touching on a few of the reasons that people love to use the USPS Flat Rate service. (Almost) Everything You Need to Know About the USPS Flat Rate Box ProgramĪs we highlighted a moment ago, the USPS Flat Rate shipping program at the post office became a runaway hit from the moment that it was first unveiled.

You can fit entire laptops inside of this box and still have space left over! The biggest of all the flat rate shipping boxes, you’ll have plenty of room to fill this large box as it measures in at 12.25” x 12.25” x 6”. Jump up to the Medium Flat Rate boxes (top loading and sideloading) and you’re looking at either 11 1⁄4 x 8 3⁄4 x 6″for the top loader or 14” x 12” x 3.5” for the side loader.įinally, you have the actual USPS Large Flat Rate Box size. These are the cheapest of the flat rate boxes and are better suited to smaller electronics, jewelry, and things of that nature. USPS Small Flat Rate Boxes measure 8.625 by 5.375 x 1.625”. Then you start getting into the box sizes. These envelopes have a bit of extra space inside of them and work great for books. Padded Flat Rate Envelopes are even larger still, measuring 12.5” x 9.5”. It’s intended (no surprise here) for use with legal documents that need to be shipped quickly yet cost-effectively. The Legal Flat Rate Envelope is slightly larger, measuring in at 9.5” x 15”. This envelope is really designed only for sending small documents, pamphlets, and other things that can slide inside of this envelope.

There are a couple of different flat rate box sizes available from the USPS, with the “large” flat rate box size being the biggest of the bunch (as of 2021, anyway). The Flat Rate Envelope is the smallest, measuring in at 12.5” x 9.5”.


Just How Big is the USPS Large Flat Rate Box Size? … And that’s just the tip of the iceberg!
