Flat rate shipping prices for small vs large boxes

What is flat rate shipping and how do prices vary between small vs large boxes? Learn pricing by box size and provider here.

Flat rate shipping prices for small vs large boxes

Flat rate shipping means efficiency for carriers, and they can pass that savings on to you. Major carriers offer flat rate shipping services, for example USPS Flat Rate Boxes.

Rather than set the price by weight, the price is set by the size of the box or envelope. Of course, the price will increase as you go up in size from a small flat rate box price, to a medium flat rate box price and to a large flat rate box price. In this article, we’ll compare flat rate options, starting with USPS Flat Rate box sizes and USPS Flat Rate Box prices.

Table of contents

1. What is flat rate shipping?

2. What are the advantages of flat rate shipping?

3. What are sizes, rates and prices for USPS Small Flat Rate Boxes?

4. What are sizes, rates and prices for USPS Medium Flat Rate Boxes?

5. What are sizes, rates and prices for USPS Large Flat Rate Boxes?

6. What are sizes, rates and prices for FedEx Small Flat Rate Boxes?

7. What are sizes, rates and prices for FedEx Medium Flat Rate Boxes?

8. What are sizes, rates and prices for FedEx Large Flat Rate Boxes?

9. How can you prepare to save on shipping and mailing costs in 2023?

What is flat rate shipping?

Flat rate shipping means you don’t have to weigh your packages: if it fits, it ships. That convenience may be reason enough to choose flat rate shipping. Potential savings is another. Generally, the cost to ship is less with a flat rate box, although that may not always be the case.

What are the advantages of flat rate shipping?

Flat rate shipping offers several advantages over other pricing models. Here are some of the biggest advantages of Flat Rate Shipping:

  • Free boxes: USPS and FedEx provide flat rate boxes at no cost. UPS offers a program that provides a subsidy for boxes.
  • Stable costs: No need to calculate prices and no surprises
  • Fast delivery: USPS Flat Rate Boxes usually arrive within 2–3 days. UPS offers several options from next-day delivery to delivery within 5 days. FedEx offers options from 1–3 business days.
  • No surcharges: USPS does not add surcharges for residential addresses, fuel or Saturday delivery. FedEx does not add fuel, residential or delivery area surcharges.
  • Large address list: USPS delivers to every U.S. address, including post office boxes, Army/Air Force Post Office (APO), Fleet Post Office (FPO) and Diplomatic Post Office (DPO).
  • Security: Only the USPS can use mailboxes, and in some cases, the USPS will try to re-deliver large packages. In addition, USPS shipments are protected by U.S. law enforcement.

We’ve already covered “What is flat rate shipping?” Your next question is likely “How much is flat rate shipping?” You’ll probably also want to know “How long does flat rate shipping take?” To answer those questions, we’ll compare costs for various package sizes and delivery speeds for both USPS and FedEx.

What are sizes, rates and prices for USPS Small Flat Rate Boxes?

USPS Flat Rate Boxes come in a few sizes, and the USPS Small Flat Rate Box is the lowest price. The Small Flat Rate Box price and details on dimensions are below.

Note that in the next few tables, you’ll see two prices for USPS Flat Rate boxes. You can qualify for the lower “commercial pricing” when you use a digital shipping service such as Pitney Bowes. The price in the last column is the higher retail rate.

Pricing for USPS Small Flat Rate Box

Length Width Height Weight Speed Commercial pricing Price at post office and online
8-11/16” 5-7/16” 1-3/4” Up to 70 lbs. 1–3 business days $8.55 $10.20

What are sizes, rates and prices for USPS Medium Flat Rate boxes?

The next size up for USPS Flat Rate Boxes is the USPS Medium Flat Rate Box. This box comes in 2 sizes and fits a variety of items such as a pair of shoes or a board game. See the table below for specifications and the medium flat rate box price.

Pricing for USPS Medium Flat Rate Box

Length Width Height Weight Speed Commercial pricing Price at post office and online
11-1/4” 8-3/4” 6” Up to 70 lbs. 1–3 business days $14.75 $17.10
11-1/4” 8-3/4” 6” Up to 70 lbs. 1–3 business days $14.75 $17.10

What are sizes, rates and prices for USPS Large Flat Rate Boxes?

If you’re looking for larger USPS Flat Rate Boxes, the USPS Large Flat Rate Box gives you more width. This box can fit a laptop and packing materials. The Large Flat Rate Box price and measurements are summarized below.

Pricing for USPS Large Flat Rate Box

Length Width Height Weight Speed Commercial pricing Price at post office and online
12-1/4” 12-1/4” 6” Up to 70 lbs. 1–3 business days $19.90 $22.80

What are sizes, rates and prices for FedEx Small Flat Rate Boxes?

The FedEx Flat Rate Box is another option for predictable pricing. The FedEx Small Flat Rate Box comes in 2 sizes and can fit a hardback book. See the table below for more information on the small flat rate box price.

Pricing for FedEx Small Flat Rate Box

Length Width Height Weight Speed Price
12-3/8” 10-7/8” 1-1/2” Up to 50 lbs. 1–3 business days As low as $12.40
11-1/4” 8-3/4” 2-5/8” Up to 50 lbs. 1–3 business days As low as $12.40

What are sizes, rates and prices for FedEx Medium Flat Rate Boxes?

The FedEx Medium Flat Rate Box gives you a little more space in each dimension. For an idea of the capacity, this box comes in 2 sizes can fit two adult T-shirts. The table below gives the medium flat rate box price. Keep in mind that a FedEx flat rate box can help you avoid hidden fees.

Pricing for FedEx Medium Flat Rate Box

Length Width Height Weight Speed Price
13-1/4” 11-1/2” 2-3/8” Up to 50 lbs. 1–3 business days As low as $16.50
11-1/4” 8-3/4” 4-3/8” Up to 50 lbs. 1–3 business days As low as $16.50

What are sizes, rates and prices for FedEx Large Flat Rate Boxes?

If you don’t want to spend time weighing packages, a FedEx Flat Rate Box can give you your time back. The FedEx Large Flat Rate Box comes in 2 sizes can fit bulkier items like a soccer ball. Here are the details on the large flat rate box price and dimensions.

Pricing for FedEx Large Flat Rate Box

Length Width Height Weight Speed Price
17-1/2” 12-3/8” 3” Up to 50 lbs. 1–3 business days As low as $24.95
11-1/4” 8-3/4” 7-3/4” Up to 50 lbs. 1–3 business days As low as $24.95

How can you prepare to save on shipping and mailing costs in 2023?

Flat rate shipping is a way to keep expenses low while adding predictability. PitneyShip® software can help you quickly compare your flat rate options across carriers. In addition, Pitney Bowes shipping software gives you discounted rates, cost accounting and real-time data and insights to help you make smarter shipping decisions across your organization.