Amazon PPC Incremental ROI Calculator

Quantify whether Amazon PPC campaigns are adding profitable revenue instead of cannibalizing organic demand. Enter organic revenue, ad-attributed sales, and ad spend, then refine margin, incremental share, and TACoS goals to surface incremental ROAS, net contribution dollars, and budget headroom for scaling.

Enter revenue generated without ad attribution for the same period.
Use Amazon's Sponsored Ads attributed sales across brand and non-brand campaigns.
Total Sponsored Products/Brands spend for the month, including coupons if deducted from budget.
Contribution margin after Amazon fees, COGS, fulfillment, and promotions. Leave blank for 35%.
Share of attributed sales that would not have happened without ads. Leave blank to assume 60%.
Target TACoS (total ad spend ÷ total sales). Leave blank to keep a 12% goal.

Business estimate only—validate with full P&L and Amazon reports before scaling spend.

Examples

  • $85,000 organic, $42,000 ad sales, $10,000 spend, 50% incremental share, 45% margin ⇒ incremental ROAS 2.10×, $4,450 incremental profit, TACoS 7.41% (4.59 pts below a 12% goal)
  • $40,000 organic, $28,000 ad sales, $12,000 spend, 45% incremental share, 30% margin ⇒ incremental ROAS 1.05×, -$8,220 incremental profit, TACoS 17.14% (5.14 pts above goal)

FAQ

How do I estimate incremental share when I lack experiments?

Benchmark 30%–50% for branded keywords, 50%–75% for non-brand search, and up to 90% for conquesting. Adjust once you can run geographic split tests, dayparting pauses, or third-party attribution.

Why is my TACoS higher than expected?

If TACoS rises, either spend grew faster than sales or organic revenue slipped. Improve product detail pages, pause low-margin ASINs, and reinvest in keywords with higher incremental ROAS.

Should I treat branded and non-branded campaigns separately?

Yes—run the calculator for each segment. Branded terms usually have lower incremental share, so you may tolerate lower ROAS while non-brand campaigns need higher true incrementality to justify budget.

Can I include coupons or deals in spend?

Include merchandising levers wherever they are debited. If Amazon deducts coupons from payouts, add them to PPC spend so incremental profit captures the full cost to acquire each order.

Additional Information

  • TACoS (total advertising cost of sales) divides ad spend by total Amazon revenue—watch for creep above 12%–15% on mature catalogs.
  • Incremental share estimates the portion of attributed sales that would not occur without ads; refine it with geo holdouts, attribution tags, or DSP clean rooms.
  • Contribution margin should deduct FBA fees, freight, returns, merchandising, and coupons so the profit figure reflects cash you actually keep.
  • Pair this output with blended ROAS and organic rank tracking to spot when ads start cannibalizing best sellers.

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