Amazon FBA Size Tier & Dimensional Weight Calculator (2025)
Size tier decides your FBA fulfillment fee more than any other factor, and a product can jump tiers by exceeding a single dimension. Enter packaged dimensions and weight to see your tier, dimensional weight, billable weight and the fee it lands on.
Packaged dimensions & weight
Measure the unit as it will be packaged when it arrives at Amazon.
Actual weight of one packaged unit.
Size tier & billable weight
The tier drives your fulfillment fee more than anything else.
Enter dimensions and weight to find your size tier.
How it's calculated
- Amazon sorts your three dimensions longest β shortest and tests them against each tier's limits in order: Small standard, Large standard, Large bulky, then Extra-large by weight.
- A unit fails a tier if it breaks any single limit. Small standard is β€ 15 Γ 12 Γ 0.75 in and β€ 16 oz; Large standard is β€ 18 Γ 14 Γ 8 in and β€ 20 lb; Large bulky is β€ 59 Γ 33 Γ 33 in, β€ 50 lb and length + girth β€ 130 in.
- Dimensional weight = L Γ W Γ H Γ· 139 (in pounds). It applies to every tier except Small standard.
- Billable shipping weight = the greater of unit weight and dimensional weight, plus packaging weight (0.25 lb standard-size, 1 lb oversize), rounded up to the next fee band.
- The fee shown is the standard (non-apparel, non-hazmat) fulfillment fee at that billable weight.
Frequently asked questions
My product is small and light β why is it Large standard?+
Almost always height. Small standard requires the shortest side to be 0.75 in or less. A padded envelope that is 1 in thick fails that single check and jumps to Large standard even if it weighs 3 oz.
When does dimensional weight matter?+
Whenever L Γ W Γ H Γ· 139 exceeds actual weight β typically light but boxy items like pillows, storage bins or anything in a large retail box. Amazon bills whichever is greater.
Can I reduce my tier by changing packaging?+
Often, yes. Trimming a box from 8.5 in to 8 in on its shortest side can drop a product from Large bulky to Large standard, cutting the fee by several dollars a unit. Test alternatives here before committing to packaging.
Is this the same as the FBA calculator?+
This page focuses on the tier and weight logic only, so you can see exactly why a product lands where it does. The full FBA calculator adds referral fees, storage and profit.