About this calculator

Break-even ACOS is the upper bound of ad spend share your unit economics can absorb before net profit becomes zero. This calculator additionally returns a Safe ACOS that reserves your target margin, so you can set responsible PPC bids before the campaign drains profit.

How to use

  1. Load a scenario preset to fill plausible cost defaults.
  2. Type your real product cost, fees and target net margin.
  3. Use Safe ACOS (not break-even) as the operational cap for new campaigns.
  4. If Safe ACOS turns negative, do not raise price — fix costs or kill the SKU.

Field reference

Sale Price
Listed price after on-page promotions, before tax.
Target Net Margin %
The net margin you want to keep after ads.
Product Cost
Per-unit landed product cost.
Referral Fee %
Marketplace category commission, e.g. 8–17% on Amazon.
Fulfillment Fee
Pick & pack / 3PL cost per unit.
Inbound Shipping
Inbound logistics per unit.
Storage Fee / Unit
Monthly storage allocated per unit.
Return Rate %
Net loss rate from returns and refunds.
Other Variable Cost
Coupons, samples, FX losses, breakage allowance.

FAQ

What's the difference between Break-even ACOS and Safe ACOS?

Break-even ACOS makes net profit exactly zero. Safe ACOS first reserves your target margin and is the cap you should bid against in real campaigns.

Why is my Safe ACOS so low?

Either fixed costs are too high, the referral category is too steep, or your target margin is too aggressive. Address the largest cost line first.

Can ACOS exceed 100%?

Yes during launch (subsidized clicks). Strategically only — long-term ACOS above the break-even line burns equity.

How do organic sales factor in?

Total ACOS (TACOS) is more accurate than ad-only ACOS once you have organic flow. Re-run with TACOS in the ad % field.

Should I include FBA inbound placement fees?

Yes, prorate them into Inbound Shipping or Other Variable Cost — they are real per-unit costs.

My competitor sells at a lower ACOS. Why?

They likely have lower COGS, longer-running listings (better organic), or a different margin tolerance — not a signal to blindly match.

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