ShippingCowCan your heavy carton clear Amazon's SFP speed bar?
Enter one carton and the ZIP you ship from. See whether it passes the carrier carton limits, and how much of the country your warehouse reaches in 2 and 5 days next to what our New Jersey, California and Texas warehouses reach.
How the check works
Enter one packed carton and the ZIP code you ship from. The check runs the carton against the UPS, FedEx and USPS carton rules, then models how much of the contiguous US your warehouse reaches in two and five ground days, next to our warehouses in New Jersey, California and Texas.
Amazon scores Seller Fulfilled Prime on the delivery date a buyer sees before buying. Reach from your ship-from point is the first thing that decides which dates you can show, so a heavy SKU with one far-off origin starts behind.
The reach uses the same method as our two-day reach study. A real plan comes from your own orders: a Saving Audit reprices your last 30 days of shipments from the closest warehouse.
Questions
What delivery speed does Amazon require for Extra Large SFP items? +
Since July 6, 2026, a two-day delivery date on at least 25% of Prime page views and a five-day date on at least 60%. Weekend page views count again from October 18, 2026. Confirm the current figures in Seller Central.
Does this check enroll me in Seller Fulfilled Prime? +
No. Enrollment and the 30-day trial belong to your Amazon seller account, and Amazon scores the trial on your Prime orders. The check shows carrier carton rules and modeled reach, nothing more.
How is the two-day reach worked out? +
From straight-line miles between your ship-from ZIP and every US ZIP area, weighted by Census 2020 population, with ground-day bands fitted to published UPS Ground transit maps. It is a model, not a carrier quote or a delivery promise.
Why compare my warehouse with three locations? +
Because one location leaves the far side of the country on a long date. In our model New Brunswick NJ alone reaches 35 to 57% of the contiguous-US population in two ground days, and New Jersey, California and Texas together reach 66 to 98%.