Amazon categorizes products into size tiers based on dimensions and weight. Your size tier determines FBA fulfillment fees. This guide explains all size tiers and how they're determined.

How Size Tiers Are Determined

Amazon uses two main factors:

1. Dimensions: Length, width, height (longest side + median side + shortest side)
2. Weight: Product weight including packaging

Standard Size Tiers (USA)

Small Standard

• Longest side: 15 inches or less
• Median side: 12 inches or less
• Shortest side: 0.75 inches or less
• Length + Girth: 84 inches or less
• Weight: 16 oz or less
• FBA Fee: $3.22

Large Standard

• Longest side: 18 inches or less
• Median side: 14 inches or less
• Shortest side: 8 inches or less
• Length + Girth: 108 inches or less
• Weight: 20 lbs or less
• FBA Fee: $4.90

Oversize Tiers (USA)

Small Oversize

• Longest side: 60 inches or less
• Length + Girth: 108 inches or less
• Weight: 70 lbs or less
• FBA Fee: $8.66

Medium Oversize

• Longest side: 108 inches or less
• Length + Girth: 130 inches or less
• Weight: 150 lbs or less
• FBA Fee: $11.37

Large Oversize

• Longest side: 108 inches or less
• Length + Girth: 165 inches or less
• Weight: 150 lbs or less
• FBA Fee: $75.78

How to Calculate Size Tier

1. Measure your product's dimensions (length, width, height) in inches
2. Sort dimensions: longest, median, shortest
3. Calculate length + girth: longest + (2 × median) + (2 × shortest)
4. Weigh your product including packaging
5. Match to size tier criteria above

Tips to Reduce Size Tier

• Optimize packaging: Use minimal, efficient packaging
• Reduce dimensions: Consider if product can be disassembled
• Reduce weight: Lighter packaging materials
• Test different configurations: Sometimes rotating dimensions helps