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Marketplace Fee-Aware Promotion Calculator

Marketplace referral fees, fulfillment fees and per-order ad spend all come out before you see a dollar of profit. This calculator factors in all three before evaluating a promotion.

e.g. Amazon category referral fee, Etsy transaction fee.

e.g. FBA pick/pack/ship fee.

Sponsored ad cost attributed to this listing per order.

Promotion

Contribution profit per order (with promotion)
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Profit without promotion
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Margin with promotion
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Total marketplace costs/order
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Volume uplift needed
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Referral fees are typically charged as a percentage of the sale price actually paid by the customer (post-discount), which this calculator applies automatically. Fulfillment fees and ad spend are treated as flat per-order costs that don't change with the promotion.

How it works

Formulas used

Payment/referral fee = Sale price × Referral fee% Contribution profit = Sale price − Product cost − Referral fee − Fulfillment fee − Ad spend

Worked example

$30 price, $8 cost, 15% referral fee, $4.50 fulfillment fee, $2 ad spend, 20% off promotion:

Marketplace fees compress promotional margin far more than a direct-to-consumer discount of the same headline size — always model them explicitly rather than assuming your normal margin cushion applies.

Related calculators

Promotion Profit Calculator
The general comparison engine, with optional fee fields.
Discount Profit Calculator
A simpler direct-to-consumer version of this analysis.

Frequently asked questions

Do referral fees apply before or after a discount?

Most marketplaces charge referral/commission fees on the actual sale price the customer pays — this calculator applies the fee after the discount, which is the more common (and more conservative) assumption.

Should I include ad spend in every promotion evaluation?

If you run sponsored ads on the listing being promoted, yes — otherwise a promotion can look profitable in isolation while still losing money once acquisition cost is included.