CartonFit

About

About CartonFit

Why CartonFit prices shipments across channels instead of packing boxes: the channel you pick moves more money than anything you do inside the box. Our three rules, and what we deliberately do not do.

Why it exists

CartonFit was built around one observation: for an Amazon FBA private-label seller shipping from China, the single biggest cost lever is not how cleverly you pack a box — it is which channel the shipment travels on, whether a carton sits a quarter inch over a size-tier cliff, and whether waiting two weeks to consolidate is worth the holding cost. Those are comparison questions. Most tools answer packing questions instead.

So the workbench prices one shipment across express, air, LCL and FCL, flags the cartons standing on an FBA fee step, and prices the trade-off between shipping a batch now and holding it back. It runs entirely in your browser — no account, no upload — because the rates that matter are yours, not ours.

Three rules we won't break

We compare. We don't quote. We don't sell freight, we don't take a cut from forwarders, and we don't show you a rate that isn't labeled with where it came from. The bundled rates are public list prices so you don't start from a blank page; the numbers that matter are the ones you type in from your own forwarder.
Every dimension is labeled. Measured, supplier-stated, derived from a rigid container, or estimated from volume — a plan built on estimates is marked as reference only.
Rates and rules carry their scope. Port-to-port is not door-to-door-with-duty. Every price on screen carries its scope on the same line, and the rules table carries the date it was verified against Amazon's published spec.

What it deliberately doesn't do

No mixed-SKU cartons, no soft-pack compression, no invented carton sizes, no duty or tariff modelling — each for a stated reason, on the limits page of the workbench. A tool that hides its limits gets used past them.

Contact

Questions, a rate source we should bundle, or a bug: email [email protected]. We read everything.