Formula
Break-even ROAS = 1 ÷ Gross margin rateDirect answer
Break-even ROAS estimates the advertising return at which gross profit equals ad spend. With a 40% gross margin, each $1 of revenue contributes $0.40 before advertising, so the campaign needs a ROAS of 1 ÷ 0.40 = 2.5×.
This is a contribution-level threshold. It does not automatically cover payroll, software, rent, taxes or other fixed operating expenses.
Read the three outputs together
| Output | Result at 40% margin | Meaning |
|---|---|---|
| Break-even ROAS | 2.5× | Required attributed revenue per unit of ad spend |
| Break-even ad cost share | 40% | Maximum ad spend as a share of revenue in this simplified model |
| Revenue per 100 ad spend | 250 | Revenue required for each 100 currency units of ad spend |
The last output uses the selected display currency as a label. No exchange-rate conversion takes place.
Use the right margin definition
Enter gross margin after product costs and other truly variable costs that you want the campaign to recover. Do not enter markup: margin and markup use different denominators.
Suppose a product sells for $100, product cost is $45, fulfillment is $8 and payment fees are $3. Three possible inputs answer different questions:
| Margin definition | Calculation | Margin | Break-even ROAS |
|---|---|---|---|
| Product gross margin only | (100 - 45) ÷ 100 |
55% | 1.82× |
| After fulfillment | (100 - 45 - 8) ÷ 100 |
47% | 2.13× |
| After fulfillment and payment fees | (100 - 45 - 8 - 3) ÷ 100 |
44% | 2.27× |
None is universally correct. The label and included costs must match the decision. A media buyer may monitor a gross-margin threshold, while a store owner may prefer a stricter contribution threshold.
Compare actual and break-even ROAS
The threshold becomes useful only when it is compared with an actual campaign result calculated from the same revenue scope.
- Actual ROAS below the threshold does not recover the entered variable-cost margin.
- Actual ROAS equal to the threshold produces no remaining contribution under the simplified assumptions.
- Actual ROAS above the threshold leaves some contribution for fixed costs and profit.
The size of that gap matters. A campaign barely above threshold has less room for refunds, attribution error or a shift toward lower-margin products than a campaign with a wider gap. Calculate actual performance with the ROAS Calculator.
When product mix changes the answer
A single margin input assumes the campaign sells a stable mix of products. If advertising shifts demand toward discounted or low-margin products, the realized margin can differ from the store average. Use campaign or product-set margin when it can be calculated consistently. Otherwise, test a range of plausible margins and note the assumption.
| Margin | Break-even ROAS |
|---|---|
| 25% | 4.00× |
| 40% | 2.50× |
| 50% | 2.00× |
| 65% | 1.54× |
Common mistakes
- Entering markup instead of margin.
- Using gross margin from one product set with ROAS from another.
- Treating the simplified threshold as full business break-even.
- Ignoring refunds, discounts, shipping subsidies or payment fees.
- Assuming margin stays constant as volume and product mix change.
Limits of this calculator
The formula assumes margin remains constant as sales volume changes. It does not model fixed costs, cash timing, taxes, inventory financing or incremental lift. Use it as a transparent campaign threshold, not as a replacement for a full profit model.
Assumptions
- Gross margin is measured before advertising spend.
- Fixed operating expenses are excluded.
Sources and methodology
CalcMotive publishes the formula and assumptions so you can decide whether the estimate fits your use case. See our methodology standards.
- OpenStax: contribution margin and contribution margin ratio; OpenStax; accessed Jul 13, 2026
- OpenStax: break-even point in units and dollars; OpenStax; accessed Jul 13, 2026