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Calculate advertising return from seller revenue, refunds, marketplace fees, product costs, and campaign spend. Build a spreadsheet comparison that preserves the attribution basis and counts each fee once.
Amazon advertising ROI is the contribution left after seller and campaign costs, divided by the campaign investment. Start with the sales assigned to the campaign, then reconcile refunds, product costs, marketplace charges, and advertising spend for the same cohort. A sales-to-spend ratio alone cannot answer whether the campaign covered those costs.
Amazon's ACoS guide defines advertising cost of sales as advertising spend divided by advertising revenue; ROAS reverses that ratio. Neither calculation is the contribution return below. The marketing ROI versus ROAS guide owns that broader distinction.
Keep the campaign ID, marketplace, currency, report dates, attribution window, and export date beside the numbers. Record whether reported sales include the refunds you later retrieve. Compare equally mature cohorts, and preserve any difference between the ad-interaction date and the financial sale date.
Do not assume an ad report provides an order-level match to every finance entry. Where the supplied reports support only a product-and-period allocation, document that allocation and retain an unreconciled amount. An estimated cost allocation should remain visibly estimated.
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Use the campaign export for attributed sales and spend, the seller transaction export for charges and credits, the returns register, and the product-cost file. Carry product identifiers into the comparison so a campaign selling a different mix receives the costs of that mix.
Amazon's selling-fee page distinguishes selling-plan and referral fees and identifies additional costs for optional services. Use the actual charges in your records rather than applying a remembered headline rate. Referral, fulfillment, storage, and return-related entries need separate classifications so finance can identify overlap.
For this calculation, contribution before marketing deducts all agreed seller costs, including allocated selling overhead where relevant. Campaign investment contains advertising and campaign management. The gross profit margin guide explains why an accounting gross margin may leave selling and delivery costs outside its boundary.
An illustrative US home-products seller reviews an August 2026 campaign cohort with returns recorded through September 30, 2026. In this example only, the report's attributed sales are before the listed refunds. Product costs are net of recoverable inventory reversals; fees are net of credits. These are assumed ledger amounts, not published Amazon fee rates.
Put the following layout in a spreadsheet with the header in row 1. Kitchen is column B, Garage is C, and Total is D. The numbered labels show spreadsheet rows.
| Row and measure | Kitchen (USD unless ratio) | Garage (USD unless ratio) | Total (USD unless ratio) |
|---|---|---|---|
| 2. Reported attributed sales | 36,000 | 24,000 | 60,000 |
| 3. Refunds and credits to sales | 2,000 | 1,000 | 3,000 |
| 4. Net attributed revenue | 34,000 | 23,000 | 57,000 |
| 5. Product cost | 12,000 | 9,000 | 21,000 |
| 6. Selling fees, net of credits | 5,400 | 3,450 | 8,850 |
| 7. Fulfillment costs | 3,600 | 2,550 | 6,150 |
| 8. Other variable and return costs | 1,000 | 500 | 1,500 |
| 9. Contribution before marketing | 12,000 | 7,500 | 19,500 |
| 10. Advertising spend | 6,000 | 4,000 | 10,000 |
| 11. Other campaign costs | 1,000 | 500 | 1,500 |
| 12. Campaign investment | 7,000 | 4,500 | 11,500 |
| 13. Contribution after investment | 5,000 | 3,000 | 8,000 |
| 14. Attribution-based ROI | 71.4% | 66.7% | 69.6% |
Attribution-based campaign ROI = (net attributed revenue − seller costs − campaign investment) / campaign investment
Enter these formulas in column B and copy them to C:
B4 = B2-B3
B9 = B4-SUM(B5:B8)
B12 = SUM(B10:B11)
B13 = B9-B12
B14 = IF(B12=0,NA(),B13/B12)
In column D, sum the two campaigns for additive rows. Calculate total ROI from dollars:
D13 = SUM(B13:C13)
D12 = SUM(B12:C12)
D14 = IF(D12=0,NA(),D13/D12)
The total is $8,000 divided by $11,500, or 69.6%, rounded to one decimal place. Both campaigns have reported-sales ROAS of 6.0 times and ACoS of 16.7%, yet their returns differ after costs. Those ratios use rows 2 and 10; the separate net-revenue-to-ad-spend ratio is $57,000 divided by $10,000, or 5.7 times.
The revenue check is $60,000 less $3,000 of refunds equals $57,000. Seller costs are $21,000 + $8,850 + $6,150 + $1,500 = $37,500. That leaves $19,500 before marketing; subtracting $11,500 leaves the same $8,000 reported above.
=D4-SUM(D5:D8)-D12-D13
This must return zero. Separately tie the input amounts to the selected exports and ledger scope. The identity catches arithmetic or classification inconsistencies; it cannot prove that missing invoices or refund records were supplied.
A settlement payout is already affected by charges and timing adjustments. Starting with that payout and subtracting every fee again understates contribution. Rebuild revenue and costs from their components, and keep reserves or payout timing separate from the expense classification.
Use advertising ROI by medium when comparing this seller result with other channels on a common cost and observation basis. A marketplace campaign's return should carry its own margin and fee boundary into that comparison.
Bring a sample of your own campaign, seller-transaction, returns, and product-cost exports to Covirage. Covirage maps the columns; its tools compute and check the figures, and the external AI model explains the result with every figure traced to its rows. Create a free Covirage account, then set up your business and bring your files.
See customer profitability for the contribution behind campaign revenue.
No. ACoS divides advertising spend by attributed advertising revenue. It does not itself deduct product cost, marketplace fees, fulfillment, or other campaign costs. ROI needs those costs and a stated investment denominator, so equal ACoS values can accompany different profit returns.
Under the campaign-investment convention used here, marketplace selling and fulfillment fees reduce contribution before advertising. Advertising and other campaign costs form the denominator. Other conventions are possible, but keep the same boundary across campaigns and never deduct the same fee twice.
Refunds reduce the matched sales cohort's revenue. Related product-cost reversals and fee credits also belong against that cohort, while unrecovered handling or disposal costs remain expenses. Use actual records and identify unresolved returns rather than assuming every refund reverses every cost.
No. Attribution assigns sales under a reporting rule; it does not show which customers would have purchased without the advertisement. A budget decision should distinguish the reconciled attributed return from any separately estimated incremental effect and disclose uncertainty in that estimate.