Start by defining the revenue you are comparing
To calculate a useful threshold, use revenue and costs with the same scope. Identify the period, products, discounts and returns included in the calculation. If the value sent to the advertising platform differs from the revenue used in business accounts, reconcile that difference before comparing reported ROAS with break-even.
Imagine a shop that records the initial order value in its advertising reporting but internally works with sales after discounts and refunds. Both numbers may be correct under their respective definitions while producing a misleading comparison. A cancelled order should not continue to support a spending decision as though it were completed.
Keep the treatment of taxes and shipping charged to the customer consistent too. For this operational analysis, you need to know which amount economically belongs to the sale and which costs correspond to it. If you include a component in revenue, do not overlook its associated cost because it appears in a different system.
Write the definition beside the report, even if it seems obvious. Choosing indicators that show whether the business is improving starts with being able to explain what each number counts and what it leaves outside the calculation.
To prepare your next step, explore Service pricing and profitability.
Calculate contribution before advertising first
The contribution margin before advertising is the share of revenue left after the variable costs associated with a sale. These may include the product, packaging, shipping paid by the company, commissions and payment processing. The selection must reflect the actual operation, while keeping this margin distinct from net profit.
In an entirely hypothetical example, consider an order with 100 euros of relevant revenue and 60 euros of variable costs before advertising. That leaves 40 euros for advertising, overhead and earnings. The contribution margin before advertising is therefore 40%: forty divided by one hundred.
If you spent the entire 40 euros on advertising to obtain that order, contribution after advertising would be zero. You would have covered the variable costs and advertising acquisition included in the example, but you would contribute nothing towards fixed salaries, premises or other business commitments. Calling the initial 40 euros profit would hide precisely that distinction.
In services, examine which costs rise when you deliver one additional contract. An existing salaried team does not behave exactly like a supplier paid per project. Classification needs to remain consistent and help reveal when growth requires additional delivery capacity.
Use the formula without losing sight of its meaning
When the entire available contribution margin can pay for advertising, operational break-even ROAS is one divided by that margin as a decimal. With a 40% margin, the calculation is 1 divided by 0.40, or 2.5. Each advertising euro must bring 2.50 euros in revenue on the basis you defined.
The same result follows directly from the order: 100 euros in revenue divided by 40 euros in advertising gives 2.5. If advertising costs 25 euros, ROAS is four and 15 euros of contribution remain after advertising. Those 15 euros still need to help pay for the company's overhead.
The formula has conditions. It assumes that the margin represents the sales being analysed and that variable costs have been identified correctly. If you combine products with very different margins, an old average may conceal the fact that a campaign mainly sells products that leave less money available.
If the available margin is zero or negative, no finite positive ROAS can achieve break-even under this model. Before increasing spending, you need to reconsider price, costs or the composition of the offer. More volume with negative contribution deepens the loss described by the calculation itself.
Preserve room for overhead and the intended result
A spending target requires a decision about how much contribution you want to preserve after advertising. If you reserve some revenue for overhead and earnings, less remains for acquisition and the required ROAS increases. That reserve needs an explicit economic justification, without being presented as a guarantee of future profit.
Returning to the example, suppose you want to preserve 15 euros per order after advertising. Of the 40 euros available before advertising, you can spend only 25. The reference ROAS becomes four because 100 divided by 25 is four; the basic formula has not changed, but the available advertising money has.
This per-order reserve needs to be tested against actual volume. Keeping 15 euros from a small number of sales may be insufficient to pay monthly overhead. Assessing the company's break-even position requires comparing total contribution with fixed costs, rather than turning one percentage into a conclusion about profitability.
Check what the platform is actually measuring
The ROAS displayed by an advertising platform relates recorded conversion value to advertising cost. To interpret it as revenue per euro spent, that value must consistently represent revenue. Measurement settings, reporting delays and attribution can separate the platform's figure from the commercial outcome that you actually want to evaluate.
A platform may receive fixed values per enquiry, order values or another measure selected by the company. If you send it 50 euros for every quotation request, the report does not prove that you received 50 euros. You are looking at an assigned event value, which needs to remain distinct from confirmed sales.
Even when you use real orders, do not automatically add together the revenue attributed by different platforms. The same purchase can appear in more than one report under each system's rules. The commercial total still needs to be reconciled with sales records, including known cancellations and adjustments.
For service businesses, start by connecting enquiries, opportunities and customers. The reasoning behind how much you can pay for a lead helps relate acquisition to economic capacity without turning a submitted form into a sale that has not happened yet.
Decide using the return on the next investment
Once you establish a coherent threshold, use it to assess the next spending increase while monitoring margin and sales composition. A comfortable average ROAS does not guarantee that additional euros will perform equally well. The decision needs to account for additional contribution, available capacity and the cash required to operate.
A campaign may first sell to customers who are already close to making a decision and then need more effort to find new buyers. It may also grow through a lower-margin product. In both cases, the previous aggregate ROAS still describes the past, but becomes insufficient as an argument for the next budget.
Record the additional spending, the corresponding sales you can identify and the costs that increased alongside them. Keep sales awaiting confirmation visible and avoid premature conclusions when there is a meaningful interval between enquiry and purchase. The calculation improves when the observation period reflects the sales cycle.
Before increasing the advertising budget, confirm which threshold you are using and why. The calculation should support a specific decision: maintain spending, test a limited increase or improve the economics of the offer, while knowing exactly which costs remain to be paid.