Is It Cheaper to Use a Flat Rate Box or Your Own Box?

Should you ship using your own box or use a carrier’s flat rate box? Both options can be cheaper depending on the item you’re shipping and how far it is going. In this blog, we’ll let you know when you should use flat rate boxes, when you should get your own box, and the pros and cons of each option.

Is It Cheaper to Use a Flat Rate Box or Your Own Box?

Depending on the nature of the item you’re shipping, the shipping distance, and the shipping service provider, either a flat rate box or your own box can be cheaper. To find out which option is cheaper among different carriers, we will compare flat-rate shipping and standard shipping options that UPS and FedEx offer.

UPS: Flat Rate Box vs. Your Own Box

Below are the size and prices for UPS flat-rate boxes:

UPS Flat Rate (Simple Rate) Box Size	Price
Extra Small (1-100 cubic inches)	Starting at $10.20
Small (101-250 cubic inches)	Starting at $13.35
Medium (251-650 cubic inches)	Starting at $16.05
Large- (651-1,050 cubic inches)	Starting at $21.05
Extra Large (1,051-1,728 cubic inches)	Starting at $26.05

The starting prices above are when you use UPS Ground for flat-rate shipping. For an accurate comparison, we will compare these flat rate prices with standard UPS Ground prices for shipping the same items.

UPS Flat Rate Box Size	Example of a shippable item	Average weight of the item	UPS Flat Rate Price (when shipping with UPS Ground)	Standard UPS Ground Rates (your own box)
Extra Small	Ceramic mug	0.6 pounds	$10.20–$10.90	$10.10–$61.37
Small	A ream of paper	5 pounds	$13.35–$13.45	$11.98–$81.89
Medium	Shoebox	2.1 pounds	$16.05–$18.15	$11.34–$71.51
Large	Regulation basketball	1.3 pounds	$21.05–$24.55	$10.90–$66.96
Extra Large	Small appliances (e.g., coffee maker)	3.5 pounds	$26.05–$29.20	$11.67–$76.91

As we can see from the table above, UPS flat rate has a higher starting cost than standard UPS Ground shipping. However, flat rate prices are lower on the upper end than standard UPS Ground.

For example, shipping a regulation-size basketball via UPS Simple Rate to the nearest zone will cost you at least $21.05. With standard UPS Ground using your own box, you would pay only $10.90.

However, as the distance increases, flat-rate shipping becomes the cheaper option. Sending the same basketball to the farthest zone with UPS Simple Rate would cost you no more than $24.55. With standard UPS Ground using your own box, you would pay $66.96.

FedEx: Flat Rate Box vs. Your Own Box

FedEx offers a flat rate shipping service that they call FedEx One Rate. Below are the rates for this service:

Service	FedEx Express Saver	FedEx 2Day	FedEx 2Day A.M.	FedEx Standard Overnight	FedEx Priority Overnight	FedEx First Overnight
Packaging type
FedEx Envelope	$11.10–$13.95	$22.00–$26.75	$30.10–$44.95	$32.95–$47.55	$41.20–$68.30	$95.20–$122.30
FedEx Pak	$11.45–$16.40	$27.40–$32.65	$35.00–$53.10	$42.05–$78.15	$50.30–$110.35	$104.30–$164.35
FedEx Small Box	$12.40–$16.95	$27.40–$33.10	$36.50–$61.35	$45.20–$87.10	$51.25–$123.50	$105.25–$177.50
FedEx Medium Box	$16.50–$21.25	$28.90–$48.70	$37.25–$77.50	$49.00–$90.55	$59.10–$139.70	$113.10–$193.70
FedEx Large Box	$24.95–$29.60	$33.75–$61.05	$38.80–$97.10	$59.10–$125.55	$65.85–$160.85	$119.85–$214.85
FedEx Extra Large Box	$39.10–$54.45	$47.80–$94.60	$48.60–$140.45	$67.10–$174.45	$78.30–$223.35	$132.30–$277.35
FedEx Tube	$39.10–$54.45	$47.80–$94.60	$48.60–$140.45	$67.10–$174.45	$78.30–$223.35	$132.30–$277.35

To find out which is cheaper, we will compare One Rate (when shipping with FedEx 2Day) prices with standard FedEx 2Day prices.

Example of a shippable item	Average weight of the item	FedEx Flat Rate Price (when shipping with FedEx 2Day)	Standard FedEx 2Day Rates (your own box)
A standard clipboard	0.5 pounds	$22.00–$26.75	$22.59–$37.55
A coffee mug	0.6 pounds	$27.40–$32.65	$22.59–$37.55
Five magazines	2.2 pounds	$27.40–$33.10	$23.89–$52.13
Two adult t-shirts	0.65 pounds	$28.90–$48.70	$22.59–$37.55
A soccer ball	0.95 pounds	$33.75–$61.05	$22.59–$37.55
Two pairs of shoes	4 pounds	$47.80–$94.60	$24.62–$59.33
A golf club	0.875 pounds	$47.80–$94.60	$22.59–$37.55

From the above rates, we can see that standard flat-rate shipping is more cost-effective when you’re using a small box and shipping the item further away. We can also see that standard FedEx 2Day is cheaper than FedEx flat rate boxes when you’re shipping lightweight items like mugs and magazines. For this reason, FedEx flat rate and other carrier flat rates are recommended for small and heavy items. Shipping lightweight items will have you pay more, as illustrated above.

What Is the Size and Weight Limit for a Medium Flat Rate Box?

Both UPS and FedEx have different sizes of boxes and envelopes, ranging from small size to extra large. Below are the size and weight limits for their medium-sized flat-rate boxes:

The FedEx Medium size flat-rate box has a maximum volume of 650 cubic inches and is available in two sizes:

-11½ in x 2⅜ in x 13¼ in
-8¾ in x 4⅜ in x 11¼ in
-11-1/2" x 2-3/8" x 13-1/4"
-8-3/4" x 4-3/8" x 11-1/4"

The general weight limit for all FedEx flat-rate boxes and envelopes is as follows:

-Packages should be at most 50 pounds. and envelopes should be at most 10 pounds.

For UPS, their medium-sized flat rate boxes have a volume of 251-650 cubic inches and are available in the following dimensions:

-8 in x 8 in x 8 in
-12 in x 9 in x 6 in
-13 in x 11 in x 2 in

General UPS Simple Rate Weight and Size Limit: If your UPS Simple Rate package exceeds one cubic foot in size (1,728 cubic inches) or weighs more than 50 pounds, you’ll have to use standard UPS rates based on dimensional weight and shipping distance.

Apart from the medium-sized flat-rate boxes, we’ve included the details of the other flat-rate packaging for FedEx and UPS below.

FedEx Flat-Rate Packaging	Available Dimensions	Maximum Volume
FedEx Envelope	9-1/2" x 12-1/2" Reusable Envelope: 9-1/2" x 15-1/2"	250 cubic inches
FedEx Pak	10-1/4" x 12-3/4" 12" x 15-1/2" Padded: 11-3/4" x 14-3/4" Reusable Sturdy Pak: 10" x 14‑1/2"	650 cubic inches
FedEx Small Box	10-7/8" x 1-1/2" x 12-3/8" 8-3/4" x 2-5/8" x 11-1/4"	420 cubic inches
FedEx Medium Box		650 cubic inches
FedEx Large Box	12-3/8" x 3" x 17-1/2" 8-3/4" x 7-3/4" x 11-1/4"	1,100 cubic inches
FedEx Extra Large Box	11-7/8" x 10-3/4" x 11" 15-3/4" x 14-1/8" x 6"	2,200 cubic inches
FedEx Tube	6" x 6" x 38"	2,200 cubic inches

UPS Flat-Rate Box Size	Available Dimensions	Volume
Extra Small	4 in x 4 in x 4 in 6 in x 4 in x 4 in 8 in x 6 in x 2 in	1-100 cubic inches
Small	6 in x 6 in x 6 in 8 in x 6 in x 5 in 12 in x 9 in x 2 in	101-250 cubic inches
Medium	8 in x 8 in x 8 in 12 in x 9 in x 6 in 13 in x 11 in x 2 in	251-650 cubic inches
Large	10 in x 10 in x 10 in 12 in x 12 in x 7 in 15 in x 11 in x 6 in	651-1,050 cubic inches
Extra Large	12 in x 12 in x 12 in 16 in x 12 in x 9 in 18 in x 12 in x 6 in	1,051-1,728 cubic inches

ShipSigma Can Help You Save Big on Shipping Small

With a partner like Shipsigma, you won’t have to search any longer for tips on how to get the lowest shipping costs. Using AI-powered software, we analyze your shipping invoice data in-depth to find and utilize the best cost-saving opportunities.

Is It Cheaper to Use a Flat Rate Box or Your Own Box?