Guides
Short, sourced explanations of the parts of Amazon's fee system that cost sellers money when they get them wrong. Every figure is computed from our tested fee data.
How Amazon FBA fees are calculated
Seven steps from a box to Amazon’s payout, with an example worked to the cent.
Amazon fee changes in 2026
Every 2026 change in date order, and what each one costs per unit.
The 3.5% fuel and logistics surcharge
What it applies to, what it adds, and why many calculators miss it.
Low-Price FBA and the $10 and $50 bands
When a lower price leaves you with more money per unit.
Ways to cut your FBA fees
Nine thresholds worth checking, with the savings worked out.
FBA profit margin, ROI and break-even
What each number tells you, and the most you can pay a supplier.
The small bulky size tier
The new 2026 tier’s limits, fees and the 130-inch trap.
Amazon dimensional weight: when you pay for the box
How the 139 divisor and the 2-inch rule decide your billed weight, with the mistake even fee tables make.
Amazon Revenue Calculator vs Feeproof
What Amazon’s own calculator does well, where an independent one helps, and how to use both.