USPS Flat Rate Box Sizes – The 10 Most Popular Sizes

Flat Rate Box Sizes are available to suit most items. This is the ultimate guide if you want to find out what is available to you. When mailing or shipping your items you need a box is going to keep your contents safe and intact when passing through the mail system. These boxes are designed to do just that.

These boxes provide you with enough options so that just about anything (within reason) can be packed and shipped. As expected the quality of the boxes is very good, have a variety of shapes and dimensions, and are very reasonable in price. The last time that I counted there were 25 different boxes available from USPS. I won’t discuss all of them here, just the most popular ones. All that you need is to do is choose the correct one according to your needs. 

In this article, I will talk about different types of USPS flat rate boxes, their sizes, and other points that I think might be relevant to you when you have to choose the correct box to use.


USPS Flat Rate Box Sizes

Table of Contents

Priority Mail – Flat Rate Box Sizes

1. Flat Rate Box Size – VARIETY PACK 

The variety pack contains four boxes – each one is a different flat rate box size. This is what you should go for if you have several different items of different sizes/shapes shipping at once. It has 1 Small flat rate box, 2 Medium flat rate boxes (1 side and 1 top), and a Large flat rate box. It comes as one complete package. Here is the Link

2. Flat Rate Box Size – SHOE BOX

The name of this box gives a pretty clear idea as to its size and shape. As the name implies, it is exactly like a shoe box. The actual dimensions are 14-7/8” (L) × 5-1/4” (W) × 7-3/8” (H). I’m sure that it will come as no great surprise to you that this box is specially designed for shipping footwear. Of course, you are not limited to just shoes – you can ship anything else that you will fit. 

This product is available for shipping in packs of ten or twenty-fiveFind them Here

3. Priority Mail – Flat Rate Box Size – MAILBOX – 1095 

This box is a bit larger than the normal flat rate box. It’s one of the most popular boxes available and is an excellent choice for domestic Priority Mail or International Priority Mail. I’ll let you decide whether this is the best one for you. Sizes are 15” (L) × 12” (W) × 3-1/8” (H).

Mailbox 1095 comes in packs of ten or twenty-five Here Is The Link

4. Priority Mail – Flat Rate Box Size – SMALL BOX 

These are the smallest flat rate boxes that USPS provides. To gauge the size of the box I would suggest thinking of 3 -4 stacked DVD cases (I guess mentioning DVDs dates me).  Actual Sizes are 8-11/16” (L) × 5-7/16 (W) × 1-3/4” (H).

The small box is available for shipping in a pack of ten or twenty-fiveGet Yours Here

5. Priority Mail – Flat Rate Box Size – FLAT RATE BOX – 2 

This box is your best companion if you have an incredibly urgent and essential shipment. According to size, this box has a prominent side loading and medium. This is one of the very new ranges of boxes issued by USPS in mid-2020. Dimensions are 14-1/8” (L) × 12” (W) × 3-1/2” (H).

This product is available for shipping in a pack of ten or twenty-five. Find Them Here

6. Priority Mail – Flat Rate Box Size – FP0/APO BOX

These boxes are solely designed for shipping Priority Mail items to Military Personnel serving overseas. This box is abbreviated as MILI_FRBX. Dimensions are 12-1/4” (L) × 12-1/4” (W) × 6”. The cost is free for these APO/FPO boxes. 

This product is available for shipping in a pack of ten or twenty-five. Get Them Here

7. Priority Mail – Flat Rate Box Size – MEDIUM BOX – 1 

This box is medium-sized (one of the most useful ‘all rounder’ of sized boxes used for shipping purposes). The abbreviation of this box is OFRB1. Sizes are 11-1/4” (L) × 8-3/4” (W) × 6” (H).

This box ships as 1 to 5 boxes and as packs of 10 or 25. Theyre Free. Get Yours Here

8. Priority Mail – Flat Rate Box Size – MEDIUM BOX 2 

This is Type 2 of the priority mail Flat Rate Medium boxes. This is a great choice for shipping items of predetermined weights either within the domestic circuit or Internationally. Other than the few changes in the size, this appears similar to the previous one. Sizes are 14-1/8” (L) × 12” (W) × 3-1/2” (H).

This box also ships as 1 to 5 boxes and as packs of 10 or 25. Free Here

9. Priority Mail ForeverFlat Rate Box Size – PRE-PAID MEDIUM BOX -1 

This box is excellent for holding large-sized books, shirts, sweaters, files, and other items of clothing, etc., and is widely used for shipping these kinds of flat-style items. This box is abbreviated as PPFRB1. This box is Not Free.

At the time of writing, it is 16.10 US dollars – per box. Remember though that you have to order a minimum of 5 boxes. Therefore, the total amount becomes $81.25

Now, for the size details of this box, it is 11-1/4” (L) × 8-4/4” (W) × 6” (H). The differences between the USPS priority mailbox and this one are quite minimal. Here’s The Link

10. Priority Mail Forever Flat Rate Box Size – PRE-PAID LARGE BOX

This is the largest box available and offered by USPS. This is abbreviated as PPLFRB. Suppose you have something a bit large, where there should be enough space for packaging. 12-1/4” (L) × 12” (W) × 6” (H).

The price of this box is $21.50 each. As with the medium box you have to order a minimum of 5 boxes. Therefore, the total amount becomes $107.50This Is The Link

Conclusion 

I’ve covered some of the most commonly used USPS Priority Mail Flat rate boxes. As you will have read, the shape and size of different boxes vary a good deal. Each of them has been designed for a specific purpose and it’s extremely unlikely that you won’t find one that is suitable for your needs.

Just take a look at the different shapes and dimensions, and go for the perfect USPS flat rate box that needs your needs. Happy shipping!

Want to know how to get the best out of your flat rate boxes? Read This Article

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