Break-Even ROAS & ACOS Calculator
Enter your profit margin — or your cost and price — to find the break-even ACOS and ROAS for your ad campaigns, plus a target ACOS/ROAS for the profit you actually want after ad spend.
ACOS, ROAS, and how they connect to margin
ACOS (Advertising Cost of Sale) is ad spend divided by the ad-attributed sales it generated: ACOS = Ad Spend ÷ Ad Sales. ROAS (Return on Ad Spend) is the same relationship flipped: ROAS = Ad Sales ÷ Ad Spend. They're reciprocals — ROAS = 100 ÷ ACOS when ACOS is a percentage, so a 30% ACOS is exactly a 3.33x ROAS. Neither number alone tells you whether a campaign is profitable; for that you need to compare it against your profit margin, which is what "break-even" means here.
Why margin sets your break-even point
Every ad-attributed sale generates a gross profit before ad costs (Margin % of the sale price). If ad spend for that sale exactly equals that gross profit, the campaign has consumed the entire margin and net ad profit is zero — that's break-even ACOS, and it's approximately equal to your pre-ad profit margin percentage. Run your ACOS below that number and the campaign is profitable on ads alone; run above it and you're spending margin (or investment budget) to buy sales, which can be a deliberate, temporary choice, but isn't free money.
A worked example
Say a product has a 30% profit margin before advertising — for every $100 in sales, $30 is gross profit and $70 is cost. Break-even ACOS is 30%: if ad spend eats exactly 30% of sales ($30 out of $100), ad profit is zero. Break-even ROAS is 100 ÷ 30 = 3.33x: sales need to be 3.33 times ad spend just to break even. Now say you don't want to just break even — you want to keep a 10% profit after ads. Target ACOS = 30% − 10% = 20%, and target ROAS = 100 ÷ 20 = 5x. That's the ACOS/ROAS you'd need to hit to actually bank profit on top of ad spend, not just cover it.
| Pre-ad margin | Break-even ACOS | Break-even ROAS |
|---|---|---|
| 15% | 15% | 6.67x |
| 20% | 20% | 5.00x |
| 30% | 30% | 3.33x |
| 40% | 40% | 2.50x |
| 50% | 50% | 2.00x |
How to find your margin if you don't know it
Switch the calculator above to "Cost & price" mode and enter your per-unit product cost and selling price — it derives margin as (Price − Cost) ÷ Price × 100 the same way the Profit Margin Calculator does, then carries that number straight into the break-even ACOS and ROAS figures. If you already sell on Amazon and want fees and fulfillment costs folded into the margin first, run your numbers through the Amazon FBA Calculator to get a net margin, then bring that figure back here.
When it's fine to advertise above break-even
Running above break-even ACOS isn't automatically a mistake. New listings often deliberately spend above break-even for a few weeks to earn reviews and initial ranking; established sellers sometimes defend a branded search term at a loss-leader ACOS to keep competitors off their listing. The key is doing it on purpose, with a plan to pull spend back down, rather than running an unprofitable campaign indefinitely without realizing it.
Go deeper with a real PPC report
This calculator works from a single margin (or cost/price) number, which is the right tool for quick planning and setting bid targets. Once you're running live campaigns, the Amazon ACOS Calculator can analyze an actual Search Term or Campaign report — upload a CSV and it surfaces high-spend zero-order terms, ACOS overruns against your target, and scale-up candidates, all processed in your browser.
Frequently asked questions
What is break-even ACOS?
Break-even ACOS is the advertising cost of sale at which your ad-generated sales exactly consume your pre-ad profit margin, leaving zero profit after ads. It's approximately equal to your profit margin percentage before advertising costs — if your margin is 30%, a campaign running at exactly 30% ACOS is roughly break-even.
What is break-even ROAS?
Break-even ROAS is the same threshold expressed as Return on Ad Spend instead of ACOS: ROAS = 100 ÷ ACOS. A 30% break-even ACOS is the same point as a 3.33x break-even ROAS — sales exactly 3.33 times ad spend, which just consumes the margin. Running below break-even ACOS (or above break-even ROAS) means the campaign is profitable on ads alone.
How are ACOS and ROAS related?
ACOS = Ad Spend ÷ Ad Sales, and ROAS = Ad Sales ÷ Ad Spend — they're reciprocals of each other, so ROAS = 1 ÷ ACOS (or 100 ÷ ACOS when ACOS is a percentage). Amazon's own console tends to report ACOS; broader marketing and DTC advertising commonly use ROAS. Neither is more correct, they're just two ways of reading the same spend-to-sales relationship.
How do I calculate my margin if I don't already know it?
Switch this calculator to "Cost & price" mode and enter your per-unit cost and selling price — it computes margin as (Price − Cost) ÷ Price × 100 automatically, then carries that margin into the break-even ACOS and ROAS figures.
What does "target ACOS for desired profit" mean?
It's the ACOS you'd need to hit to keep a specific profit margin after ad spend, rather than just breaking even. Target ACOS = Margin % − Desired post-ad profit %. For example, a 30% margin with a 10% desired post-ad profit needs a target ACOS of 20% (and a target ROAS of 5x).
Is break-even ACOS the same as a "good" ACOS?
Not necessarily. Break-even is the point where ad profit is zero — it's a floor, not a goal. Many sellers deliberately run above break-even for a launch, a ranking push, or brand defense, accepting little or no ad profit for volume or visibility. Others target comfortably below break-even to bank ad profit on an established listing. For deeper analysis of an actual PPC report, see the Amazon ACOS Calculator's report analyzer.
Last updated: July 2026 · How we calculate
BriskToolbox provides estimates for general information only and is not financial or advertising advice. Verify figures against your own margin and Amazon Ads reporting before making budget or bid decisions.