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Packaging and box size calculator

Enter the product without its box. The calculator tries seven box sizes around it and recommends the cheapest one with at least a quarter inch of padding per side.

Uses Amazon's US rates checked October 18, 2026. Runs in your browser; nothing you type is sent anywhere.

The product, unboxed

in
in
in
lb
lb
lb
Single-wall corrugated is about 0.05–0.1.
$
Best box saves per unit vs 1 in of padding
$0.00
    Fees by box sizePadding is added to every side. Fulfillment fee includes today's surcharge and any peak rate; storage is one month at today's rate.
    Padding per sideBox (in)WeightTierBilled weightFulfillmentStorage / mo

    How box size changes FBA fees

    Three things move when the box grows. The size tier can change: a box more than 0.75 in thick leaves small standard, and one longer than 18 in leaves large standard. Dimensional weight can overtake the real weight: length × width × height ÷ 139 for every tier except small standard. And storage is charged on cubic feet, so it rises with every inch.

    The largest box that still bills on a given weight has a volume of that weight × 139 cubic inches. A 12 oz unit (0.75 lb) can sit in up to 104 cubic inches, about 8 × 6 × 2.2 in, before dimensional weight pushes it into a higher row.

    Protect the product first: damaged units cost more than any fee saving. Use the table to find padding that is safe and stays inside the cheaper row. See also the dimensional weight guide.