Marketing ROI: how to calculate it and what it really tells you.

Most ad accounts look healthy on paper. A ROAS of 480% sits in the dashboard, the agency report is green, and yet the business has less money at the end of the quarter than the numbers suggest. The gap is almost always the same: revenue was treated as profit, and only part of the cost was counted. Marketing ROI closes that gap, because it asks the one question that matters to the owner of the budget. Did this money come back, and how much more came with it?

This guide covers what marketing ROI is, the formula, and why one campaign can honestly be reported as 33%, 100%, 300% or 480% depending on the numbers you plug in. You will find two worked examples (an online store and a service business that sells through enquiries), a calculator for your own figures, the difference between ROI, ROAS and POAS, what a good ROI looks like, why the average hides the return on your next euro, why SEO pays back on a different clock than ads, and how to measure it in Google Ads, GA4 and Meta. Definitions come from Google’s own help pages. At Viralistic we report marketing in exactly these terms: gross profit, every cost and ROI per channel. A green ROAS has never paid anyone’s rent.

What is marketing ROI?

ROI stands for return on investment. It expresses the profit an investment produces as a percentage of what the investment cost. Marketing ROI, sometimes shortened to MROI or ROMI (return on marketing investment), applies the same idea to your marketing spend. At 0% you break even. Above 0% your marketing earns back more than it costs. Below 0% it loses money.

Google puts it plainly in its Google Ads help article on ROI: “ROI is the ratio of your net profit to your costs.” Google also calls it typically the most important measurement for an advertiser, because it shows the real effect your advertising has on your business. Clicks and impressions tell you how many people you reached. ROI tells you whether reaching them paid.

Because ROI is a percentage, it lets you compare investments of very different sizes on equal terms: a EUR 500 test against a EUR 50,000 campaign, or a new website against a year of SEO. Within your marketing metrics it is the KPI that sums up the rest. Cost per click, conversion rate and cost per lead are the levers. ROI is the outcome.

One caution before the formula. In investing and real estate, return is usually quoted per year. In marketing you normally calculate it per campaign, month or quarter. A 20% ROI on a three-month campaign is a different thing from a 20% annual return on a fund, so do not compare the two directly. To put returns over different periods side by side, annualise them: annual ROI = (1 + ROI)^(12 ÷ months) - 1. A 20% return over three months, repeated at the same rate, compounds to roughly 107% a year.

The marketing ROI formula

The formula itself is short. The real work is in deciding what counts as return and what counts as cost.

Marketing ROI = (gross profit from marketing - marketing cost) ÷ marketing cost × 100%

Subtract the cost from the return, divide by the cost and multiply by 100 to get a percentage. In Excel or Google Sheets, put the cost in cell B1 and the gross profit in B2, then enter =(B2-B1)/B1 in a cell formatted as a percentage.

To get a figure you can trust, work through it in this order:

1. Decide what you are measuring and over which period, for example one campaign over one quarter.
2. Add up every cost it took to produce the result, not only the media budget.
3. Calculate the return as gross profit: revenue excluding VAT or sales tax, minus the cost of the goods or service delivered, minus refunds and returns.
4. Apply the formula and compare the result with the same calculation for an earlier period or another channel.

What counts as return

For marketing, the return is the gross profit your marketing produced, not the revenue. Revenue includes money that was never yours to keep: the supplier, the production cost and the tax office all take their share before anything lands with you. Many guides use revenue in the formula for simplicity. It makes ROI look several times better than your bank balance, and it makes a low-margin business look as healthy as a high-margin one.

What counts as cost

On the cost side, include everything it took to get that return. The media budget is usually only part of it.

Google’s definition versus the marketer’s

Google calculates ROI differently from most marketers, and it is worth knowing both. In the Google Ads example, a product costs $100 to produce and sells for $200. You sell six through Google Ads for $1,200 in sales, and the ads cost $200. Google treats production plus advertising as the investment: ($1,200 - $800) ÷ $800 = 50%. For every $1 spent, you get $1.50 back.

A marketer usually asks a narrower question: what did the marketing budget return? Then only the $200 is the investment and the return is the $600 gross profit, which gives ($600 - $200) ÷ $200 = 200%. Both answers are correct, because they answer different questions. Google itself notes that the exact method depends on the goals of your campaign. Pick one definition, write down how you calculate it and stick to it, so campaigns and periods stay comparable. The rest of this guide uses the marketer’s version: gross profit against all marketing costs.

How to calculate marketing ROI: two worked examples

The difference between an honest ROI and an inflated one is easiest to see with real-looking numbers. Both examples below use illustrative figures.

Example: an online store

An online store selling handmade ceramics spends EUR 5,000 on ads in a month, plus EUR 1,000 on creative and management. Total marketing cost is EUR 6,000. The campaigns bring in EUR 24,000 in revenue, excluding VAT. The gross margin is 50%, so the gross profit is EUR 12,000.

Marketing ROI = (EUR 12,000 - EUR 6,000) ÷ EUR 6,000 × 100% = 100%

Every euro of marketing came back, plus another euro of profit. Now look at the other numbers the same campaign can produce. Calculated on revenue, the ROI is (EUR 24,000 - EUR 6,000) ÷ EUR 6,000 = 300%. The ad platforms report a ROAS of EUR 24,000 ÷ EUR 5,000 = 480%. And with Google’s definition, where product cost and marketing together are the investment, it is (EUR 24,000 - EUR 18,000) ÷ EUR 18,000 = 33%. Four figures for one campaign: 33%, 100%, 300% and 480%. Only the 100% tells the owner what the marketing budget actually earned.

Run the numbers for your own business below. The calculator uses gross profit and all marketing costs, and shows ROAS alongside for comparison.

Example: a service business that sells through enquiries

If you sell services, your ad account shows enquiries, not revenue, so you calculate through leads and clients. Take a B2B consultancy in Amsterdam that spends EUR 9,000 in a quarter: EUR 7,000 on LinkedIn and Google Ads and EUR 2,000 on management and content. That brings in 45 enquiries, so the cost per acquisition (CPA) per enquiry is EUR 200. Nine of them become clients, which puts the customer acquisition cost (CAC) at EUR 1,000. If a new client brings EUR 4,000 in gross profit in the first year, the quarter produced EUR 36,000 in gross profit.

Marketing ROI = (EUR 36,000 - EUR 9,000) ÷ EUR 9,000 × 100% = 300%

Two lessons sit inside this example. The number of enquiries means little until you know how many turn into clients: if only one in ten closes instead of one in five, gross profit halves and the ROI drops to 100%. And the first year is rarely the whole relationship. If clients stay, calculate with customer lifetime value instead of one year. The real ROI is then higher, and you can afford to pay more to win a client than the first project suggests.

ROI vs ROAS vs POAS

ROI, ROAS and POAS look alike but answer different questions. ROAS divides revenue by ad spend. POAS divides gross profit by ad spend. ROI compares the profit left over with the full investment.

ROAS is what Google Ads and Meta optimise for by default, because they know your revenue but not your margin. A high ROAS can still lose money when margins are thin. POAS fixes the margin problem by working with gross profit, but it still only looks at media spend. ROI is the widest of the three and also includes management, creative and your own time. In practice, you use ROAS or POAS to steer day to day, and ROI to decide whether a channel deserves its place in the budget.

The chart shows why ROAS alone is not enough. Every bar has the same ROAS of 500%, with ad spend as the only investment. The only thing that changes is the gross margin.

At a 20% margin, a 500% ROAS only breaks even. Below that it loses money on every sale. That is why your break-even ROAS is 1 ÷ gross margin. How to work it out, and how to set a target ROAS from it, is covered in how to calculate ROAS.

What is a good marketing ROI?

A good marketing ROI is one above your own floor. There is no single percentage that holds for every business, and tables of average ROI by industry say little unless you know how they were calculated. The online store example showed one campaign landing anywhere between 33% and 300% depending on the definition alone.

You will often read that a 5:1 ratio is good marketing ROI. Check what sits behind a figure like that. If it means five euros of revenue for every euro of marketing, it is a ROAS of 500%, and the chart above shows that at a 20% margin that only breaks even. A rule of thumb based on revenue cannot tell a profitable campaign from a loss-making one.

The hard floor is 0%, calculated on gross profit and all costs. Above that, your marketing pays for itself. Whether a given ROI is good after that depends on your situation. A high margin makes a high ROI easier to reach. When clients stay for years, the first sale may return little or nothing and still be worth it. The period matters: 30% in a quarter is more than 30% in a year. And the same euro might earn more elsewhere, in a better website, in SEO or in keeping the clients you already have.

A negative ROI is not always a mistake either. A first test campaign costs money and mainly buys knowledge: which message lands and which audience responds. Agree on that up front and it is a deliberate investment. A campaign that stays below zero month after month is not.

Incremental and marginal ROI: the questions behind the average

The ROI you calculate from your accounts is an average, and it credits marketing with every sale it touched. Two sharper questions sit behind it. Incremental ROI counts only the sales that would not have happened without the campaign. Marginal ROI asks what the next euro will return, not what the last ten thousand did.

Meridian, Google’s open-source marketing mix model, puts numbers to both. In the example in Google’s Meridian documentation, a shoe store spends $10,000 on video ads and the model estimates $25,000 in sales that would not have happened otherwise: $2.50 back per dollar. If the channel is close to saturation, the next dollar might return only $0.80. The average still looks healthy, yet extra budget there would lose money. Meridian’s ROI divides incremental revenue by spend, so you still apply your gross margin before you call it profit.

Without a data team, the practical version is a holdout test. Pause a campaign in one region or for a few weeks and compare the enquiries with a period or region where it ran. Brand campaigns often fail this test, because many of those clicks came from people already on their way to you.

Why timing changes ROI: SEO, ads and payback

The ROI of an investment depends on when you measure it. Ads return money straight away and stop when the budget stops. SEO and content cost money first, return it later and keep working afterwards. Measure SEO after three months and the ROI is almost always negative, which says more about the measurement date than about SEO.

The worked example below makes this visible. A business invests EUR 2,000 a month in SEO and content for a year. In the first month that returns nothing. After that, gross profit from organic clients grows by EUR 500 a month: EUR 500 in month 2, EUR 1,000 in month 3, and so on. These are assumptions to show the mechanism, not a promise. In your market it can go faster, slower or not at all, which is exactly why you measure it.

In this example the ROI is -75% after three months and -38% after six. The investment is paid back in month 9, and after twelve months the ROI is 38%. The visibility you built keeps working after that, even if you invest less. Ads do not behave this way: switch the campaign off and the return stops with it.

The time it takes for an investment to earn itself back is the payback period. With an even return, the formula is simple: payback period = investment ÷ gross profit per month. A EUR 8,000 website that adds EUR 1,000 a month in gross profit pays for itself in eight months. When the return builds gradually, as with SEO, add it up month by month until cumulative gross profit catches up with cumulative investment.

So choose the measurement period before you start, and match it to the investment and to your sales cycle. For a search campaign that can be a month. For SEO, content or a new website, a year is a fairer horizon.

How to measure ROI in Google Ads, GA4 and Meta

No ad platform shows your ROI out of the box, because no platform knows your margin or your other costs. What they do measure is conversions and conversion value. From there you either calculate ROI yourself or let the platform work with profit instead of revenue.

Google Ads: it all starts with conversion value

In Google Ads, you give every conversion a value: the order value for a purchase, or an estimated value for an enquiry. According to Google’s article about conversion values, the Conversion value/cost column then helps you track your campaigns’ ROI. Strictly speaking that column is your ROAS, since it divides revenue by ad spend. You get closer to ROI by sending gross profit as the conversion value instead of revenue. Google mentions this option itself: Target ROAS maximises conversion value, “such as sales revenue or profit margins”. For how the auction and bid strategies work, see search engine advertising explained.

For lead generation, give each enquiry the value of an average enquiry. Google does the maths in its own example: if one in ten leads becomes a $20 sale, each lead is worth $2 on average. It gets more accurate when you send closed deals from your CRM back to Google Ads. That is what enhanced conversions for leads is for: it measures which leads became customers using first-party data from your CRM, hashed before it is sent to Google. You then see not only which campaign brings enquiries, but which campaign brings clients.

GA4: all channels side by side

Google Analytics 4 measures revenue and key events (the events formerly called conversions) across all your channels. Costs from a linked Google Ads account flow in automatically. Costs from Meta, LinkedIn or email come in through campaign data import, which was previously called cost data import. Google Analytics combines those costs with the revenue it already measures, and you find the result under Reports, Acquisition, Non Google campaign, and in the Advertising workspace. Keep your UTM tags consistent everywhere: Google points out that “Facebook” and “facebook” are not an exact match, and unmatched rows do not join your session data.

Meta Ads Manager and Search Console

Meta Ads Manager reports ROAS based on the conversion value that the Meta pixel or the Conversions API passes on. Like Google Ads, it knows nothing about your margin or other costs. For SEO, Google Search Console shows how many clicks you get from organic search and for which queries. Search Console does not measure enquiries or sales, so the return on those clicks comes from GA4 or your CRM.

Attribution: who gets the credit?

A client sees an ad on Instagram, searches your name a week later and books a call through an organic result. Meta, Google Ads and GA4 can each claim that one client. Add up the platform reports and you count the same revenue two or three times. Calculate your overall marketing ROI from a single source, such as your accounts, your CRM or GA4, and use the platform numbers to steer within each channel.

How to improve marketing ROI

You can improve ROI from both sides of the formula: more gross profit from the same spend, or the same gross profit for less money. The biggest gains rarely sit in the ad itself.

Your website is usually the strongest lever. If a landing page converts twice as well, every euro you send to it returns twice as much. That is why conversion rate optimisation often does more for ROI than extra budget. Your message comes next. A clear story attracts the right people and filters out the wrong ones, which lowers your cost per client. Your channel mix matters too: the more you are found through SEO, the fewer visitors you have to buy. And keeping existing clients makes every client you ever won worth more. This is the reason our marketing starts organic: the foundation first, then paid campaigns as an accent on top.

On the cost side, cut what produces nothing: search terms that bring clicks and no clients, audiences that never buy, and brand campaigns that mostly reach people who were already looking for you. Then test rather than guess. An A/B test shows two versions of an ad or page to comparable audiences, so you know which one works better instead of assuming it.

Common mistakes when calculating marketing ROI

If an agency runs your campaigns, ask for reporting in these terms: gross profit, all costs and ROI per channel, not only clicks and ROAS.

How we help

Viralistic is a strategic digital partner in Amsterdam, founded and led by Marrallisa Kreijkes. We measure what matters to your business: how many enquiries come in, how good they are and what a new client costs you. Clicks and impressions are tools for getting there, not the goal. We read marketing ROI the way this guide calculates it: on gross profit, with every cost on the table, over a period that suits the channel.

Before a single euro goes to ads, we check the foundation: a clear message built on your brand script, a fast website that turns visitors into enquiries, measurement you can trust, and visibility in Google and in AI answers. When that is healthy and you want more, we run Google Ads and Meta Ads as an accent on top, built on your brand script. We test broadly first, review the numbers with you and only then move budget to what demonstrably works. Sometimes our honest advice is that ads are not the right next step yet, and we will tell you so. Read more about our marketing approach and about SEO and AI search.

Frequently asked questions

How do you calculate marketing ROI?

Subtract your total marketing costs from the gross profit your marketing generated, divide by the marketing costs and multiply by 100. If a campaign costs EUR 6,000 and brings in EUR 12,000 in gross profit, the ROI is (12,000 - 6,000) ÷ 6,000 × 100% = 100%. Use gross profit rather than revenue, and include management, creative, tools and your own time in the costs.

What is a good marketing ROI ratio?

A good marketing ROI ratio is any ratio that still leaves profit after your gross margin and all costs. The often-quoted 5:1 usually means five euros of revenue per euro spent, which at a 20% margin only breaks even. Set your floor at 0% ROI on gross profit, then judge everything above it against your margin and how long clients stay.

What does a 30% ROI mean?

A 30% ROI means every euro invested came back with 30 cents of profit on top: spend EUR 1,000 and end up with EUR 1,300. For a quarterly campaign measured on gross profit and all costs, that is a solid result. Measured on revenue, the same 30% can hide a loss once product costs and VAT come off.

Is 3% a good ROI?

For an annual investment, such as savings or bonds, 3% a year can be reasonable. For a marketing campaign it is thin: 3% on gross profit means the campaign barely earns back its own cost, with little room for error, refunds or a slower month. Marketing ROI is usually measured per campaign or quarter, so compare it with your own targets, not with interest rates.

What is the difference between ROI and ROAS?

ROAS divides revenue by ad spend only. ROI compares profit with all costs. So a 500% ROAS can still mean a negative ROI: at a 15% margin, EUR 5 of revenue leaves EUR 0.75 of gross profit for every EUR 1 of ads. Use ROAS to steer inside an ad platform and ROI to judge whether the money was well spent.

What is the difference between ROI and MROI?

MROI, marketing ROI, applies the ROI formula to marketing alone: the profit your marketing produced against what the marketing cost. ROI on its own can describe any investment, from a machine to a fund. In marketing mix modelling, a lowercase mROI means something else again: marginal ROI, the return on the next euro you spend.

Is a 2.2 ROAS good?

It depends on your margin. Your break-even ROAS is 1 ÷ gross margin, so a ROAS of 2.2 (220%) is only profitable when your gross margin is above roughly 45%. At a 60% margin, 2.2 leaves a healthy profit on ad spend. At a 30% margin, the same 2.2 loses money on every sale. Calculate your own break-even point before judging any ROAS.

Can ROI be negative?

Yes. A negative ROI means the return is lower than the cost, so the investment lost money. At -100% the full investment is gone. A negative ROI can be acceptable for a deliberate test campaign or for SEO in its first months, as long as you have agreed in advance when the investment needs to pay back and what you will learn along the way.

How do you calculate the ROI of SEO?

For SEO, the return is the gross profit from clients who arrived through organic search, and the cost is what you invest in content, technical work and authority, or your agency’s fee. Track those clients in GA4 or your CRM, because Search Console does not measure conversions. Measure over at least a year: SEO costs money first, returns it later and keeps working after that.

What is the 70/20/10 rule for marketing budget?

The 70/20/10 rule splits a marketing budget into 70% for proven activity, 20% for building on what already works and 10% for experiments. Coca-Cola is the brand most often linked to it. Judge each part on its own terms: the 70% should show a positive ROI, while the 10% buys knowledge and may return nothing at all.