USPS Shipping Cost Calculator
Enter USPS postage, packaging, insurance, add-ons, buyer-paid shipping, and unit count to see seller-paid shipping impact and per-item shipping cost.
$2.38
total shipping cost minus buyer-paid shipping
$9.37
postage, packaging, insurance, add-ons
$9.37
allocated across 1 unit(s)
The buyer-paid shipping charge does not cover the full cost stack, so the difference reduces profit.
Match shipping cost to marketplace fee data
Seller-paid shipping changes net payout differently depending on the marketplace fee model. Use the Fee Index for same-input marketplace rows, Fee Changes for recent policy updates, and Seller Reports for dated summaries before deciding whether a shipping strategy still works.
After the source check, use this tool to allocate postage, packaging, insurance, and add-on costs to the listing or lot.
Turn this result into a listing decision
Use the tool result as a starting point, then test payout, break-even price, shipping, and marketplace fit before you publish the listing.
What this calculator includes
Shipping profit usually changes after the label is bought because packaging, insurance, signature confirmation, and marketplace shipping charge settings all land in different places. This tool puts those costs in one view.
It does not quote live USPS rates. Use the postage amount from your label provider or USPS checkout, then add packaging and add-on costs to measure the real seller-paid shipping impact.
Related tools
Use break-even when shipping changes the minimum viable price, margin after platform fees, and COGS when lot buys need cost allocation before shipping is added.