Marketing and acquisition
Return on ad spend (ROAS) calculator
Return on ad spend is the revenue a campaign produced for every unit of money put into it. Divide campaign revenue by campaign spend. The result is a ratio, so 4:1 means four units of revenue came back for every one spent.
Revenue from the campaign, not total revenue
Media plus agency fees and creative
The formula
- Revenue
- The revenue the campaign produced, not the revenue the business produced while the campaign was running. Those are different numbers and the second one is always larger. Take the figure from your own analytics rather than the ad platform where you can, since the platform is grading its own work. Tagging campaigns consistently with a UTM builder is what makes that possible in the first place.
- Ad spend
- Everything spent to run the campaign. Media cost is the obvious part. Agency retainer, creative production, and the licence for whatever tool built the landing page all belong here too. Media-only spend is the default in most reporting and it makes every campaign look better than it was, sometimes by a third or more for smaller budgets where fixed costs weigh heavily.
A worked example
An outdoor gear brand spends 10,000 on a paid campaign for a quarter and attributes 40,000 in revenue to it. That is a 4:1 ROAS, which clears the rule of thumb the agency quoted, so the campaign gets renewed and the budget gets increased.
The brand keeps 30 percent of revenue after the cost of the goods. So the 40,000 in revenue is 12,000 in gross profit, and 10,000 of that went to the ads. The campaign made 2,000. A ratio that reads like the money quadrupled produced a contribution of two thousand units on a ten thousand unit bet.
The number that would have shown this immediately is the break-even ROAS, which is 1 divided by the gross margin. At a 30 percent margin that is 3.33:1, so 4:1 is a pass but a narrow one. At a 25 percent margin break-even would be exactly 4:1 and the campaign would have profited nothing at all while still hitting the industry benchmark. Work out your own break-even figure with the gross margin calculator before judging any campaign against a number you read somewhere.
When to use it
ROAS is at its best comparing campaigns, creatives, or channels against each other inside the same business, over the same period, at the same margin. Everything the ratio leaves out is held constant in that comparison, so what remains is a fair read on which advertising worked harder.
It is the right tool when the question is narrowly about advertising. That is its advantage over ROI, which can cover an entire initiative but depends on a longer chain of assumptions about which outcomes belonged to which effort. A shorter chain is a more defensible number, which is why ROAS survives scrutiny in a meeting that ROI does not.
Read it against your break-even ratio rather than against a benchmark. Anything above 1:1 returned more revenue than it cost, but revenue is not profit, and the point where a campaign starts genuinely making money sits at 1 divided by your gross margin. That figure is specific to your business and it is the only threshold worth managing to.
Where it misleads
ROAS ignores margin completely, and this is the failure that costs real money. Two businesses posting an identical 4:1 are in entirely different positions if one keeps 60 percent of revenue and the other keeps 20. The ratio cannot tell them apart, and the industry rules of thumb quoted in agency decks are written as though margin were a constant.
The revenue figure is an attribution claim, not a fact. Ad platforms count conversions against their own campaigns generously, including customers who would have bought anyway and returning buyers who came through a paid link out of habit. Platform ROAS and analytics ROAS routinely differ by a wide margin, and the truth is usually nearer the lower of the two.
Spend nearly always means media only. Add the agency fee, the creative, and the staff time and the real ratio drops, sometimes sharply on smaller budgets. If you want the number that includes all of it, the question you are actually asking is customer acquisition cost, which is built to hold those costs.
It also stops at the first purchase. A 2:1 on a product that gets repurchased quarterly is a better business than a 5:1 on something bought once, and ROAS cannot see the difference. Where repeat purchase matters, judge acquisition against lifetime value instead of against the first order.
Finally, an average hides the shape of the spend. The first thousand units of budget reach the people most likely to buy and the last thousand reach the least likely, so a blended 4:1 can conceal a marginal ratio well below break-even. Scaling a campaign on its average is how a profitable programme becomes an unprofitable one without any single report ever looking wrong.
Frequently asked
What is a good ROAS?
It depends on gross margin, not on the industry. Divide 1 by your gross margin to find the ratio where a campaign breaks even. At a 30 percent margin that is 3.33:1, so anything above it contributes profit and anything below it loses money regardless of how the figure compares to a published benchmark.
What is the difference between ROAS and ROI?
ROAS divides revenue by ad spend and is expressed as a ratio, so it measures advertising alone. ROI subtracts total cost from total profit and is expressed as a percentage, so it can cover an entire initiative. ROAS is narrower and easier to defend, ROI is broader and rests on more assumptions.
Should ROAS use revenue or profit?
Revenue, by definition. That is exactly why the ratio has to be read against a break-even figure derived from margin. A version using profit instead is a different and more useful measure, but it is no longer ROAS and should not be compared against anyone else figures.
Why does the ad platform report a different ROAS than analytics?
Platforms attribute conversions to themselves using view-through and long click windows, which counts buyers who would have purchased anyway. Analytics typically uses a stricter last-click model. The gap is attribution methodology, not a bug, and the conservative figure is the safer one to budget against.
Does ad spend include agency fees?
It should, though most reporting excludes them. Media cost alone flatters the ratio, and on a small budget a retainer and creative production can account for a third of the total invested. Decide which definition you are using and apply it consistently across every campaign you compare.
Numbers are the easy part
Getting the calculation right takes two inputs. Getting an organization to agree on what counts as gain, what counts as cost, and what the number should change takes considerably longer.
That translation work is most of what I do. Westphal Solutions builds websites, tools, and reporting for nonprofits and growing teams, including the kind of measurement setup that makes a number like this one worth trusting in the first place.
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