Marketing ROI calculator

How the number is worked out

ROAS is revenue divided by spend. Gross profit is revenue multiplied by gross margin. Break-even ROAS is 1 divided by gross margin. Return on marketing spend is gross profit less spend, divided by spend, shown as a percentage. Cost per new customer is spend divided by new customers, and gross profit per customer is gross profit divided by new customers. The profit left over is gross profit less spend.

Benchmarks worth comparing against

A worked example, with the arithmetic shown

A B2B services company spends $6,000 in a month across ads, content and agency fees, and can trace $30,000 of new revenue to it. Twelve first-time customers signed. Gross margin is 45%.

ROAS is $30,000 divided by $6,000, so 5.0. Gross profit is $30,000 multiplied by 0.45, so $13,500. Break-even ROAS is 1 divided by 0.45, so 2.22. Return on marketing spend is $13,500 less $6,000, divided by $6,000, so 125%. Cost per new customer is $6,000 divided by 12, so $500, and gross profit per customer is $13,500 divided by 12, so $1,125.

The month cleared $7,500 of gross profit after paying for the marketing. Now change one input. Drop the margin from 45% to 20% and the same 5.0 ROAS is exactly break-even: gross profit falls to $6,000 and the profit left over is zero. The spend, the revenue and the customer count never moved.

How to read the result

Read ROAS against break-even ROAS, never on its own. That pairing is the whole point of the tool, and it is the number most calculators omit. A 4x return sounds decisive until you notice your margin demands 5x.

Then read cost per new customer against gross profit per customer. If it costs $500 to win a customer who leaves $1,125 of gross profit behind on the first sale, the channel funds itself immediately. If those two numbers cross over, you are buying customers at a loss and relying on them coming back, which is a legitimate strategy only when you have measured your repeat rate rather than assumed it.

For context on the spend side rather than the return side, Gartner’s 2026 CMO Spend Survey put marketing budgets at 7.8% of company revenue, and LocaliQ’s 2026 benchmarks put the average paid-search cost per lead at $66.69. Both are reference points, not targets. Your margin decides what you can afford.

ROI, ROAS and ROMI are three different questions

They get used interchangeably in the same meeting, which is how a campaign ends up approved on one number and judged on another.

ROAS is revenue divided by ad spend. It ignores the cost of delivering the sale entirely, which makes it quick to calculate and useless as a profit signal on its own. Marketing ROI and return on marketing investment, or ROMI, both work in profit: gross profit less spend, divided by spend. That is the figure this calculator leads with, and it is the one a finance team will recognise.

Use ROAS to compare two campaigns with each other, since the delivery cost is the same on both sides. Use the profit version to decide whether the month made money. And never quote a ROAS without its break-even beside it, because on its own it is a measurement with no threshold attached.

What this calculation does not account for

• Repeat purchases. A customer worth $900 once is a different proposition from one worth $900 a year for four years. A channel that looks unprofitable on the first sale can be the best one you have.
• The sales cycle. If your average deal takes three months to close, this month’s revenue was bought by spend from three months ago. Offset the figures rather than comparing the same month with itself.
• Attribution. Revenue you cannot trace back to the spend should be left out, even when you strongly suspect the spend helped. Overstating attributed revenue is the most common way this calculation flatters a channel.
• Fixed costs. Gross margin sits above overheads, so a positive figure here is not the same thing as a profitable business.

The figures you type are worked out in your browser. Nothing is sent to us, nothing is stored, and there is no email field to get past first.

When to stop calculating and talk to someone

Stop when the answer stops changing. If you have run three or four honest scenarios and every one says the same thing, the arithmetic has done its job and the remaining question is operational. Two situations in particular are not solved by another pass through a calculator.

The first is when the return is positive but small, and the lever that would move it is not the budget. Doubling a landing page conversion rate does the same work as doubling spend and usually costs less, which is a build question rather than a media one.

The ad budget calculator shows exactly how much each lever is worth, and the website ROI and payback calculator tells you whether the site receiving that traffic is worth the money at all.

The second is when you cannot fill the fields honestly. If you do not know which revenue came from which channel, the problem is measurement, not marketing, and no ROI figure calculated on top of it is safe to act on. That is the first thing our digital marketing service fixes, because everything after it depends on it.

If you want to see how the same numbers behave on the organic side of the ledger, our post on SEO versus PPC ROI for small businesses runs the comparison. If you already know what you want to spend, the published starting prices are on the offers and pricing page, and marketing retainers there exclude ad spend so the two are never confused.

Bring a month of real figures to a free consultation and we will tell you which of them we think is wrong.