- Is this the same math the paid app uses?
- Yes. The public calculator and the authenticated app read the same versioned fee table. If the paid app's number is ever different, that's a bug.
- Why does the split-ship path not always win?
- Because freight + pick-and-pack labor across multiple FCs can exceed the placement fee on small shipments. That's the entire point of the comparison — "split-ship is always cheaper" is not true, and tools that assume it are wrong.
- What's the 5-Carton Rule?
- Amazon waives all inbound placement fees on shipments of ≥ 5 cartons if every carton has the same item mix and the same quantities per carton. Three conditions, often missed. The 5-Carton checker walks you through them.
- Does prep padding change the fee?
- Yes — packed dimensions (raw dimensions + prep padding) are what Amazon uses for size-tier lookup. Products within one inch of a tier boundary can cross it once you add a poly bag or bubble wrap. See the size-tier checker to catch it at catalog-entry time.
- Why don't you ask me to log in to Amazon?
- Because Amazon's SP-API packing endpoints have been broken since 2024. CrateFit works on the numbers you enter directly and doesn't depend on endpoints that don't work.
- What fee version did you use?
- Every result shows the version label and effective date next to the total. Click it to see the source rows.
