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  • Writer's pictureBrian Cummings

Amazon FBA Seller Size Tiers and FBA Fees Explained: 2024

Updated: Apr 8

If you want to succeed on Amazon, you need to know Amazon Size Tiers. Smart sellers optimize their products and packaging with a size tier in mind so that they can save money on FBA Fees and get a competitive advantage over traditional brands that usually use one package size for all their channels. Optimizing for Amazon's specific size tiers is paramount to your success.

So, what are size tiers? In short, they're categories that Amazon uses to group products based on their dimensions and weight. Depending on your product's size tier, you'll pay different storage and fulfillment fees, which can significantly impact your profits.

You might also want to discover how to simplify inventory management on Amazon by reading this article on the Power of an Amazon Inventory Report.

Product Size Key Terms

To understand Amazon FBA size tiers, you need to be familiar with key terms like unit weight, product dimensions and volume, and dimensional weight.

Unit weight refers to the weight of the product when fully packaged and ready to be shipped.

Product dimensions and volume are calculated by multiplying the length, width, and height of the product.

Dimensional weight takes into account the package's size in relation to its weight, and Amazon uses the greater of the unit weight or dimensional weight to determine the product size tier.

Understanding these terms is crucial for accurately determining a product's size tier and avoiding unexpected fees.

Unit Weight

Unit Weight is also called the actual weight. It's the weight of the product including the packaging. It's fairly straightforward, you just need to weigh the product in it's package on a scale.

Calculating the unit weight of your product is essential in understanding the FBA fees you'll be charged, as it determines the weight of your product when fully packaged and ready to be shipped.

Product Dimensions and Volume

To accurately determine your product's size tier, you'll need to calculate its volume by multiplying its length, width, and height.

This information will also be used to calculate the dimensional weight, which takes into account the package's size in relation to its weight. Amazon uses the greater of the unit weight or dimensional weight to determine the product size tier.

Dimensional Weight and How to Calculate It

Even if your product is lightweight, it may be charged as if it were heavier if it takes up a lot of space in the warehouse and during shipping.

The formula used to calculate dimensional weight is typically length x width x height (in inches) / a dimensional weight factor.

In Amazon’s case, that factor is 139, which is most common within the US shipping industry standard; it is 5,000 for calculating the DIM weight of packages shipped across the UK/Europe.

Therefore, if your package exceeds the threshold for its size tier based on its dimensional weight, you may end up paying more in fees even if the actual weight is low.

Amazon is shifting to using Dimensional Weight in more and more fee calculations over the past few years. Currently Dimension Weight is used for FBA Fulfillment fees, FBA removal order fees, FBA disposal order Fees, MCF fulfillment fees, and FBA inventory Placement Service fees.

Amazon FBA Size Tier Chart

​Product Size Tier

Unit Weight

Longest Side

Median Side

Shortest Size

Length + Girth

Small standard-size

​16 oz

15 inches

12 inches

0.75 inch


Large standard-size

20 lb

18 inches

14 inches

8 inches


Small oversize

70 lb

60 inches

30 inches


130 inches

Medium oversize

150 lb

108 inches



130 inches

Large oversize

150 lb

108 inches



165 inches

​Special Oversize

Over 150 lb

Over 108 inches



Over 165 inches

Best FBA Dimension and Fee Calculators

These Amazon FBA Calculators can help you understand all the FBA fees involved in selling a particular product - everything from monthly FBA storage costs and fulfillment fees to referral fees and more. You can also play around with dimensions and see how much you can save by optimizing your size tiers.

Examples of Products and their Size Tiers

Take a look at some real-life examples of products and the size tiers they fall under on Amazon FBA. Seeing how different items fit into the different categories can help you better understand the importance of correctly calculating your product's size.

For example, a pack of playing cards would fall under the small size tier with dimensions of 5.25 x 3.5 x 0.75 inches and a unit weight of 0.2 pounds.

A pair of running shoes, on the other hand, would fall under the standard size tier with dimensions of 13 x 8 x 5 inches and a unit weight of 1.5 pounds.

A set of golf clubs would be classified as oversize with dimensions of 48 x 15 x 12 inches and a unit weight of 15 pounds.

Finally, a kayak would fall under the super oversize tier with dimensions of 144 x 25 x 17 inches and a unit weight of 80 pounds.

These examples show how important it is to accurately determine your product's size tier, as it can greatly affect your storage and shipping fees on Amazon FBA.

Size Tiers and Amazon Fees

You'll be pleased to know that understanding the various size tiers on Amazon will help you save money and increase profits, as package dimensions directly impact shipping and storage costs.

Amazon FBA fees are determined by the size tier of your product, with standard size products weighing 20 pounds or less and having specific dimensions. Oversize and super oversize packages have higher fees, making it important to accurately determine your product's size tier.

To calculate FBA fees, shipping weight, dimensional weight, and unit weight are used. Storage fees are based on daily average volume in cubic feet, and costs vary based on time of year and package size. Long-term storage fees can be avoided with good FBA inventory management and minimized with a good prep center or 3pl like Prep It Pack It Ship It.

Staying on top of FBA package dimensions is crucial for success as an Amazon seller, as it directly impacts costs and profitability.

Read more about how to speed up Amazon FBA Check-in Times in 2024 here.

Blackhat Tactic - When Competition Messes with your Package Size

An old blackhat tactic of Amazon sellers to mess with the competition was devastatingly effective. They would send in oversize units on other sellers listing, and from that point, every sale of that product by the original seller was charged as oversize, making the original seller's profits disappear overnight.

Stay on top of this by using tools like AMZAlert that alert you when your package dimensions change so that you can request a cubiscan in the fulfillment center and make sure you're getting charged accurate prices by Amazon.


By now, you understand the importance of knowing your product's size tier and how it impacts your fees and overall success on the platform. You've learned about the different size tiers, how to determine your product's size tier, and examples of products and their corresponding tiers.

So, whether you're a seasoned seller or just starting, take this information and apply it to your business strategy with Prep It Pack It Ship It. Remember to stay up-to-date on any changes to Amazon FBA size tiers and fees and adjust accordingly.

With this knowledge and a little bit of effort, you can achieve success on Amazon FBA and take your eCommerce business to the next level.

Curious about how to liquidate inventory on Amazon? Find out how here.

Frequently Asked Questions

If you're looking for more information on Amazon FBA product sizing, you might have some questions - here are some commonly asked ones.

What should I do if my product's size tier seems incorrect?

Double-check your measurements and make sure you're using the correct formula for calculating dimensional weight. If you still believe the size tier is incorrect, contact Amazon Seller Support for assistance.

How often do Amazon FBA size tiers change and what factors contribute to these changes?

Amazon FBA size tiers can change due to market dynamics, customer preferences, and business strategies. Changes occur periodically, and staying informed is crucial for business planning. Amazon Seller Central, FBA calculator, blogs/forums, and online courses are helpful resources.

Can sellers request a reassessment of their product's size tier if they believe it has been incorrectly categorized?

Yes, you can request a reassessment of your product's size tier if you believe it has been incorrectly categorized. Contact Amazon's Seller Support with your product's dimensions and weight, and they will review your case and adjust the size tier if necessary.

Are there any alternative fulfillment options available for sellers who want to avoid FBA fees?

Yes, there are alternative fulfillment options available for sellers who want to avoid FBA fees. These include using a third-party fulfillment service or fulfilling orders themselves through their own warehouse or storage facility.

What are the different size tiers on Amazon?

Amazon has two main tiers - Standard and Oversize, and 6 classifications - small standard, large standard, small oversize, medium oversize, large oversize, and special oversize

How are Amazon FBA fees calculated?

Amazon FBA fees are calculated based on several factors including the size and weight of the product, the time of year, and the product category. These fees include a storage fee, a fulfillment fee, and potentially long-term storage fees if a product remains in a fulfillment center for over 365 days.

What is the Amazon FBA calculator and how does it work?

The Amazon FBA calculator is a tool that helps sellers estimate the fees associated with using Amazon's fulfillment service for their products. By inputting information such as the product's size and weight, the seller can get an idea of how much they should expect to pay in fees.

What are the fees associated with using Amazon FBA?

The fees associated with using Amazon FBA include a per-unit fulfillment fee, a monthly inventory storage fee, and potentially long-term storage fees for items that remain in the fulfillment center for more than 365 days. Additional fees may also apply for oversized items or products with unusual dimensions.

How does Amazon determine which size tier a product falls under?

Amazon determines which size tier a product falls under by measuring the product's longest side, its median side, and its shortest side. They use a cubiscan, which is a special machine that precisely measures a product. The weight of the product is also taken into account when determining the size tier.

How often do Amazon FBA fees change?

Amazon FBA fees typically change once a year, with changes usually taking effect in February. However, Amazon may make adjustments to fees throughout the year as needed.

What is the difference between unit weight and dimensional weight?

Unit weight is simply the weight of the product itself, while dimensional weight takes into account the product's size as well. Amazon uses whichever

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