Seller Margin & Tariff Calculator
Tariffs and marketplace fees quietly eat reseller margins. This calculator turns your supplier cost, duty rate, freight, and fees into a true landed cost — then shows your real net margin, markup, ROI, break-even price, and the price you'd need for a target margin.
Landed cost = product cost + freight + duty (tariff rate × product cost) + CBP fees (MPF 0.3464% + HMF 0.125% ≈ 0.47%). Net profit = selling price − landed cost − marketplace/payment fees − other per-unit costs. The tool also shows margin (profit ÷ price), markup (profit ÷ cost), ROI, your break-even price, and the price needed to hit a target margin.
Landed cost (what one unit costs you delivered)
Selling side
Duty and CBP fees here are applied to the product's customs value, not to freight/insurance (which US customs value usually excludes when stated separately). Confirm your exact rate from your product's HTS code.
Marketplace/payment fees are estimated as a flat percentage of price; check your platform's exact referral + processing schedule, plus any per-item or FBA fees, which you can add under 'other costs'.
Estimate for planning — verify your exact rates.
Find your product’s duty rate from its HTS code, and confirm CBP fees and your platform’s fee schedule:
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How to use Seller Margin & Tariff Calculator
- 1Enter your product cost, freight, duty/tariff rate, and CBP import fees to build the landed cost.
- 2Enter your selling price, marketplace + payment fee percentage, and any other per-unit cost.
- 3Optionally set a target margin to solve for the price that reaches it.
- 4Read your net profit, margin, markup, ROI, and break-even — plus warnings on thin or negative margins.
What 'landed cost' really includes
Landed cost is what one unit actually costs you delivered and cleared through customs: the supplier price, international freight and insurance, the import duty (your product's tariff rate applied to its customs value), and the CBP fees — the Merchandise Processing Fee (0.3464% of goods value) and, for ocean shipments, the Harbor Maintenance Fee (0.125%).
Most 'margin calculators' ignore duty and fees entirely, which is exactly what turns a healthy-looking markup into a loss once a tariff is applied. Duty and the CBP fees are charged on the goods' customs value, not on freight or insurance when those are stated separately.
Margin vs markup vs ROI — they're not the same
Margin is profit as a percentage of your selling price; markup is profit as a percentage of your cost; ROI is profit against the cash tied up in inventory (landed cost). A 50% markup is only a 33% margin, so mixing them up is a fast way to underprice.
The break-even price is the lowest price you can charge before you start losing money — and because marketplace fees are a percentage of price, it isn't simply your cost; the tool solves for it correctly.
Pricing for a target margin
Enter a target margin and the calculator solves for the selling price that reaches it after fees — useful when a new tariff forces a re-price. If the marketplace fee alone is larger than the headroom your target leaves, the tool tells you the target isn't reachable rather than showing a misleading number.
Frequently Asked Questions
How do I find my product's tariff rate?
Look up your product's HTS (Harmonized Tariff Schedule) code at hts.usitc.gov — the rate shown there is the duty percentage to enter. If you're unsure of the classification, a licensed customs broker can confirm it; the wrong code means the wrong duty.
What are MPF and HMF?
They're US Customs fees. The Merchandise Processing Fee (MPF) is 0.3464% of the goods' value; the Harbor Maintenance Fee (HMF) is 0.125% and applies only to ocean shipments. Combined they're roughly 0.47%, which is the default here — adjust it if you ship by air (no HMF).
Is margin the same as markup?
No. Margin is profit divided by your selling price; markup is profit divided by your cost. The same dollar of profit gives a bigger markup number than margin number, so always be clear which one a supplier or marketplace is quoting.
Does this include Amazon FBA or per-item fees?
The marketplace field covers percentage-based referral and payment fees. Add flat per-unit fees like FBA fulfillment, pick-and-pack, or storage under 'other cost per unit' so the margin reflects them.
Is my financial data uploaded anywhere?
No. Every calculator on this site runs entirely in your browser — nothing you enter is sent to a server.