Does FedEx Charge by Weight or Size? (Your Full Guide)

There’s so much to think about when it comes to shipping with FedEx. First, you have to choose which service to use, then you have to choose the correct size box, and on top of that, you have to estimate your shipping costs.

All of that can be pretty overwhelming. That’s why we’ve put together this guide to help you understand how FedEx’s pricing works. More specifically, we’ll let you know whether or not FedEx charges by weight or size, so keep reading!

Does FedEx Charge by Weight or Size In 2024?

FedEx uses both weight and size when calculating shipping rates in 2024. Packages can be priced using either dimensional weight or the actual weight of the package, whichever is greater. Dimensional weight is calculated by multiplying a package’s length by its width and height in inches and then dividing by 139. Dimensional weight encourages customers to pack more efficiently.

We understand that FedEx’s shipping costs can be confusing to understand, so we hope you keep reading until the end to learn more useful facts!

How Does FedEx Calculate Shipping Costs?

FedEx calculates shipping prices using either the dimensional weight (often shortened to dim weight) or the actual weight of the package, whichever is greater.

It’s important to note that dim weight reflects a package’s density. In other words, it’s the amount of space a package occupies in relation to its actual weight.

Therefore, it’s usually the case that the bigger and heavier your shipment is, the more it costs.

That’s also the reason why it’s important to choose a box that’s big enough to accommodate your items and packing materials (e.g. bubble wrap or packing peanuts), but not so big that it increases the package’s dim weight for no reason.

How Does FedEx Calculate Dimensional Weight?

To calculate the dimensional weight of a package, multiply the package’s length by its width and height in inches. Round each measurement to the nearest whole inch.

This result is the package’s cubic size. Then, divide by 139 for domestic and international shipments.

Here is the formula to calculate dimensional weight: LxWxH/139= total cubic square inches.

If you don’t feel like doing the math, you can also use FedEx’s dimensional weight calculator.

Why Is Dimensional Weight Important to FedEx?

Why Is Dimensional Weight Important to FedEx?

There are 3 main reasons why dimensional (dim) weight is important when shipping with FedEx. Let’s take a look at what they are:

  1. FedEx uses dim weight to calculate shipping prices.
  2. Dim weight pricing may reduce shipping costs for customers who pack more efficiently.
  3. Reducing packaging can make shipments more environmentally friendly by helping to lower fuel emissions. It can also help customers avoid overpacking and wasting material.

To make things even clearer, imagine how often people ship using packaging that’s too big. When a box is a lot bigger than its contents, extra cushioning is needed.

These over-packed boxes fill shipping trucks with cubic feet of unnecessary corrugated cardboard and air cushioning. Put simply, people are literally paying to ship air.

That’s why FedEx rewards customers who pack efficiently with low prices.

When people use the smallest possible packaging, FedEx is able to fit more products on trucks and planes, something that increases the bottom line as well.

How Does Dimensional Weight Vary Between Different FedEx Services?

Different FedEx services use dimensional weight differently. Let’s take a closer look:

FedEx Express

Any shipments using the customer’s own packaging use dim weight. Dim weight can also apply to FedEx packaging.

For domestic shipments, dimensional weight is used on a per-package and per-shipment basis.

For international shipments, dim weight applies per shipment. If the dim weight is higher than the actual weight, then the dim weight will be used.

FedEx Ground

For FedEx Ground, dimensional weight is applied for all shipments on a per-package basis. If the dim weight is higher than the actual weight, then the dim weight will be used.

If a package weighs more than 150 pounds, a prorated per-pound rate is used.

FedEx Home Delivery

If a residential delivery package has a weight greater than 70 pounds, then it’s handled the same way as a Ground package having the same weight and being shipped under similar circumstances.

FedEx Ground Economy (SmartPost)

Ground Economy (formerly known as SmartPost), a joint service offered with the United States Postal Service, uses dim weight pricing.

Are There Other Factors That Affect FedEx’s Shipping Rates?

Besides weight and size, there are many other factors that go into determining FedEx’s shipping rates.

Perhaps the most important factor in estimating price is the service a customer chooses (e.g. Overnight, Home Delivery, Ground Economy).

Still, things like fuel costs, delivery and pickup conditions, special handling requirements, and extenuating circumstances that affect network capacity all impact pricing as well.

To know more, you can also read our posts on how long does FedEx hold packages, what happens when FedEx package is stolen, and if you can use duct tape on FedEx packages.


It may seem obvious, but FedEx is first and foremost a business. Therefore, its goal will always be to maximize profits. Using weight-based and dimensional-based shipping is just one of the ways the company increases its bottom line.

With this model, FedEx can charge based on size or weight, whichever is greater. This may seem greedy, but it actually encourages customers to pack efficiently so they’re not paying to ship half-full boxes.

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Marques Thomas

Marques Thomas graduated with a MBA in 2011. Since then, Marques has worked in the retail and consumer service industry as a manager, advisor, and marketer. Marques is also the head writer and founder of

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