Margin Seller

Independent marketplace research

Walmart™ & Amazon™ Profit Calculator for Sellers

Review Walmart™ and Amazon™ listings in one product-research workflow. Start with a supported public listing, add your own costs, and compare estimated unit profit, ROI, break-even price, and a clear next step.

Start with the listing price and your supplier cost. Include marketplace referral fees, fulfillment and shipping, advertising, storage, and returns to estimate per-unit profit. Compare the resulting margin and return on investment with your target before purchasing inventory. Fees are editable planning assumptions, not live marketplace quotes; verify current rates with the marketplace.

Run a free margin audit · See how it works

What the audit shows

  • Estimated profit and margin after product, selling, and fulfillment costs
  • Return on investment, break-even price, and maximum buy price
  • A planning signal for reviewing the assumptions before buying

Learn more about marketplace costs

Explore profit calculators, seller guides, marketplace comparisons, sourcing playbooks, and seller terminology.