FedEx Box Sizes Cheat Sheet: Dimensions & Weight Limits (2026)
FedEx box sizes run from the flat FedEx Small Box (12.25" x 10.9" x 1.5" inside) through the Medium and Large Boxes to the much deeper 10kg and 25kg international boxes, plus a Tube, Pak and Envelope. FedEx-branded boxes are free, but you can use them only with FedEx Express services. Anything shipping FedEx Ground has to go in your own box. This cheat sheet lists the inside dimensions and weight limits FedEx publishes, then covers One Rate, weight limits and how box size affects dimensional weight.
Updated October 28, 2026. Dimensions and limits checked against fedex.com in September 2026.
FedEx box sizes cheat sheet
The table below lists the inside dimensions and weight limits FedEx publishes for its branded Express packaging. We took each figure from the product pages on fedex.com. Two things stand out. The Small, Medium and Large Boxes are all shallow, document-style boxes (1.5" to 3" deep), not cubes. Only the 10kg and 25kg boxes are deep enough for bulky goods.
| FedEx packaging | Inside dimensions | Max weight (per FedEx product page) | Designed for |
|---|---|---|---|
| FedEx Envelope | 9.252" x 13.189" | 17.6 oz (500 g) | Documents, up to about 60 pages |
| FedEx Large Pak | 12" x 15.5" | 5.5 lb (2.5 kg) | Heavier documents; tear- and water-resistant |
| FedEx Small Box | 12.25" x 10.9" x 1.5" | 20 lb (9.07 kg) | Catalogs, file folders, CDs |
| FedEx Medium Box | 13.25" x 11.5" x 2.38" | 20 lb (9.07 kg) | Binders, books, heavy documents |
| FedEx Large Box | 17.88" x 12.38" x 3" | Not listed here (FedEx pages conflict) | Side-by-side paper stacks, small parts, reports |
| FedEx Tube | 38" x 6" x 6" x 6" (triangular) | 20 lb (9.07 kg) | Plans, posters, blueprints, fabric rolls |
| FedEx 10kg Box | 15.81" x 12.94" x 10.19" | 22 lb (10 kg) for the flat rate | FedEx International Priority |
| FedEx 25kg Box | 21.56" x 16.56" x 13.19" | 55 lb (25 kg) for the flat rate | FedEx International Priority; double-walled |
Sources, checked September 2026: FedEx packaging pages for the Envelope, Large Pak, Small Box, Medium Box, Large Box, Tube, 10kg Box and 25kg Box. These are FedEx's regional English pages. FedEx sometimes stocks more than one version of a box, so check the dimensions printed on the box or in your FedEx supplies order before you plan around them.
FedEx box dimensions by size
FedEx Small Box dimensions
The FedEx Small Box measures 12.25" x 10.9" x 1.5" inside and holds up to 20 lb, according to FedEx. It's only 1.5" deep, so it works for flat items like catalogs, file folders, thin apparel, prints or a phone case. It won't fit a 10" cube-shaped product. If you need a small but deeper container, check whether the newer Extra Small Box or a Medium Box fits.
FedEx Medium Box dimensions
The FedEx Medium Box measures 13.25" x 11.5" x 2.38" inside and holds up to 20 lb, according to the FedEx Medium Box page. Like the Small Box, it's a flat, document-style box. It suits binders, books and heavy documents rather than deep products.
FedEx Large Box dimensions
The FedEx Large Box measures 17.88" x 12.38" x 3" inside, according to the FedEx Large Box page. It's a wide, flat box. FedEx says it's for side-by-side paper stacks, small parts and reports. It is not an 18" cube, even though many older guides described it that way. For taller items, look at the Extra Large Box, the 10kg or 25kg box (international only), or your own carton.
FedEx Extra Small and Extra Large Boxes
FedEx lists a FedEx Extra Small Box and a FedEx Extra Large Box as One Rate packaging on its One Rate page. The Extra Small Box became available on February 2, 2026, according to the FedEx One Rate pricing guide. FedEx doesn't publish dimensions for these two boxes on the pages we checked, so we've left them out of the table rather than guess. Check the size printed on the box or in your FedEx supplies order.
FedEx Pak, Tube and Envelope sizes
The FedEx Large Pak measures 12" x 15.5" and holds up to 5.5 lb. The FedEx Tube is a triangular tube measuring 38" x 6" x 6" x 6" that holds up to 20 lb, for plans, posters and rolled items. The FedEx Envelope measures 9.252" x 13.189" and holds up to 17.6 oz, or about 60 pages. For every FedEx envelope and Pak option, see our FedEx envelope sizes guide.
FedEx 10kg and 25kg Boxes
The FedEx 10kg Box measures 15.81" x 12.94" x 10.19" inside, and the 25kg Box measures 21.56" x 16.56" x 13.19". They're the only deep FedEx boxes, and they're for FedEx International Priority flat-rate shipping. To qualify for the flat rate, contents can't exceed 10 kg (22 lb) or 25 kg (55 lb).
What are the FedEx weight limits by box and service?
FedEx sets weight limits per box, per pricing program and per service. These are the limits FedEx publishes on the pages we checked:
- FedEx Envelope: 17.6 oz (500 g) per the product page. Under One Rate, Envelopes must weigh 10 lb or less.
- FedEx Large Pak: 5.5 lb (2.5 kg) per the product page.
- FedEx Small Box, Medium Box and Tube: 20 lb (9.07 kg) each.
- FedEx One Rate: Paks, boxes and tubes must weigh 50 lb or less.
- FedEx 10kg and 25kg Boxes: 10 kg (22 lb) and 25 kg (55 lb) for the international flat rate.
- FedEx Ground and Home Delivery (your own box): up to 150 lb, 108" in length and 165" in length plus girth.
Are FedEx boxes free, and who can use them?
Yes. FedEx-branded Express packaging is free, but only for FedEx Express shipments. The FedEx Express Packaging Supplies Policy says FedEx provides "complimentary FedEx branded packaging." It also says these options "may not be used to ship via FedEx Ground or FedEx SmartPost," via another carrier, or for resale. The same policy says FedEx may seek damages for misuse of your account.
FedEx's packaging page adds that complimentary packaging is available for FedEx expedited services, FedEx Express Saver and select FedEx international standard services. You can pick up FedEx boxes in store or order them online.
Key term: FedEx Express is FedEx's air-based, time-definite network (overnight, 2Day, Express Saver and international priority services). FedEx Ground and FedEx Home Delivery are its truck-based, day-definite networks.
How does FedEx One Rate work with FedEx boxes?
FedEx One Rate is a flat-rate pricing option. You pay one price based on the FedEx package you use, the service, and the destination zone, without weighing or measuring the package. The FedEx One Rate page says it lets you "ship packages anywhere in the U.S. for a fixed price." It covers expedited domestic services, including FedEx Express Saver, FedEx 2Day, FedEx 2Day A.M. and overnight services. FedEx also states that "FedEx standard services shipping is not available with FedEx One Rate pricing."
These One Rate rules come from FedEx's current One Rate pricing guide:
- One Rate box sizes: Only FedEx packaging qualifies: the Envelope, Pak, Extra Small, Small, Medium, Large and Extra Large Boxes, and the Tube.
- Weight caps: FedEx Envelopes must weigh 10 lb or less, and FedEx Paks, boxes and tubes 50 lb or less.
- Stuffed envelopes and Paks: A One Rate Envelope more than 3" thick, or a Pak more than 5" thick, is rated as a One Rate box based on its cubic volume.
- Dry ice: Dry ice isn't permitted with any One Rate shipment.
One Rate prices change with FedEx's rate updates, so get current figures from the FedEx One Rate pricing PDF or the FedEx rate tool. We don't list prices here. One Rate usually pays off when the item is small but dense, like tools, supplements or metal parts. Standard weight-based pricing would charge a lot for those, while One Rate charges only for the box.
What is dimensional weight, and how does box size affect it?
Dimensional (DIM) weight is a billable weight based on how much space a package takes up, not how much it weighs. FedEx charges whichever is greater: the actual weight or the DIM weight. According to FedEx's dimensional weight page, you calculate it by rounding each measurement to the nearest whole inch, multiplying length x width x height, and dividing by 139 for U.S., Puerto Rico and international shipments.
Here's how that plays out with typical box sizes (worked examples using FedEx's formula):
| Box (rounded inches) | Cubic inches | DIM weight (÷139) |
|---|---|---|
| FedEx Large Box footprint, 18 x 12 x 3 | 648 | About 4.7 lb |
| Your own 12 x 12 x 12 box | 1,728 | About 12.4 lb |
| Your own 16 x 16 x 16 box | 4,096 | About 29.5 lb |
A 3 lb pillow shipped in a 16" cube could be billed at almost 30 lb. Moving the same product into a box a few inches smaller in each direction can cut its billable weight by more than half. That's why box choice often matters more than carrier choice for light, bulky ecommerce products. One Rate avoids DIM math entirely for qualifying Express shipments. For everything else, try our free dimensional weight calculator before you order cartons.
When should you use your own box with FedEx Ground?
Use your own box whenever you ship FedEx Ground or FedEx Home Delivery, because FedEx Express branded packaging isn't allowed on those services. Most ecommerce orders ship this way. FedEx lists these FedEx Ground limits:
- Packages up to 150 lb.
- Up to 108" in length.
- Up to 165" in length plus girth (L + 2W + 2H).
- Delivery in 1–5 business days within the contiguous U.S., and 3–7 business days to and from Alaska and Hawaii.
Your own box also makes sense when your products are cube-shaped or taller than 3". The standard FedEx Small, Medium and Large Boxes are too shallow for those. Plain corrugated boxes are available from packaging suppliers, and FedEx Office also sells them in store; the FedEx boxes page lists sizes from 8" x 8" x 8" up to 28" x 28" x 28". Pick the smallest box that protects the product with adequate cushioning. Extra empty space gets billed as DIM weight.
How do you choose the right FedEx box?
Start with the service. If a shipment is going FedEx Express, check whether a free FedEx box fits and whether One Rate beats weight-based pricing. If it's going Ground, size your own carton as tightly as the product allows. A quick checklist:
- Measure the packed item, including cushioning, and compare it to the inside dimensions in the table above.
- Match box to service: use FedEx boxes only for FedEx Express services, and your own box for Ground and Home Delivery.
- Compare billable weight: work out actual vs. DIM weight (L x W x H ÷ 139) for your own box, and compare it with the One Rate price for the matching FedEx box.
- Standardize a few SKU-specific sizes so every order doesn't go out in the same oversized box.
- Rate-shop carriers: the cheapest option by weight and zone changes from order to order. Our breakdown of FedEx vs. UPS costs and our guide to rate shopping and carrier selection go deeper.
For more ways to trim postage, including packaging right-sizing, see how to reduce ecommerce shipping costs.
How does Atomix Logistics handle FedEx packaging for ecommerce brands?
Atomix Logistics is a third-party logistics (3PL) and order-fulfillment company for ecommerce and DTC brands, with month-to-month agreements and no long-term contracts. We pick, pack and ship your orders, rate-shop UPS, FedEx and USPS for each shipment, and choose packaging that keeps billable weight down. You can see how our fulfillment process works or get a quote on our order fulfillment pricing page.
Frequently asked questions
What size is a FedEx Small Box?
The FedEx Small Box measures 12.25" x 10.9" x 1.5" inside and holds up to 20 lb, according to FedEx's packaging page. It is a flat box built for catalogs, file folders and similar thin items, so it will not fit a cube-shaped product. It is free, but only for FedEx Express shipments.
What are the FedEx Large Box dimensions?
The FedEx Large Box measures 17.88" x 12.38" x 3" inside, according to FedEx. It is wide and shallow, intended for paper stacks, small parts and reports, not an 18-inch cube. For taller items, consider the FedEx Extra Large Box, the international 10kg or 25kg box, or your own carton shipped via FedEx Ground.
What is the weight limit for FedEx boxes?
The FedEx Small Box, Medium Box and Tube each hold up to 20 lb, the Large Pak 5.5 lb and the Envelope 17.6 oz, per FedEx's product pages. Under One Rate, Paks, boxes and tubes can weigh up to 50 lb. Your own box shipped FedEx Ground can weigh up to 150 lb.
Are FedEx boxes free?
Yes. FedEx-branded Express packaging is complimentary, but FedEx's packaging supplies policy says it may be used only for FedEx Express shipments. It cannot be used for FedEx Ground, FedEx SmartPost, another carrier or resale, and FedEx may seek damages for misuse of your account.
Can I use a FedEx box for FedEx Ground?
No. FedEx states that its Express branded packaging is for FedEx Express shipments only and may not be used to ship via FedEx Ground. For Ground or Home Delivery, use your own corrugated box. Those services accept packages up to 150 lb, 108 inches long and 165 inches in length plus girth.
How does FedEx One Rate work?
FedEx One Rate charges a flat price by FedEx package, service and zone, with no weighing or measuring, for U.S. expedited services such as Express Saver, 2Day and overnight. Envelopes must weigh 10 lb or less and Paks, boxes and tubes 50 lb or less. It is not available with FedEx Ground.
How do I calculate FedEx dimensional weight?
Round each side to the nearest whole inch, multiply length by width by height, then divide by 139 for U.S., Puerto Rico and international shipments. FedEx bills the greater of actual weight or dimensional weight, so a 16-inch cube can be billed at about 29.5 lb even if the item inside is light.
What are the FedEx 10kg and 25kg boxes?
They are larger FedEx boxes for FedEx International Priority flat-rate shipping. The 10kg Box measures 15.81" x 12.94" x 10.19" inside, and the 25kg Box measures 21.56" x 16.56" x 13.19". To qualify for the flat rate, contents cannot exceed 10 kg or 25 kg respectively.
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