Marketing ROI Measurement: How to Calculate It (Simple Guide)
Marketing ROI measurement sounds like it should be simple: did the money you spent bring back more money than it cost? In practice, most people get stuck somewhere between "I know the formula" and "I have no idea what my actual number is," because the data lives in three different places and none of them talk to each other.
Here's the straightforward version — the formula, what it needs, and where people usually get lost.
The formula
Marketing ROI = (Revenue from marketing − Marketing cost) / Marketing cost × 100
That's it. If a campaign cost you €1,000 and brought in €3,000 in revenue, your ROI is (3,000 − 1,000) / 1,000 × 100 = 200%. You made two euros for every euro spent.
Where the numbers actually come from
Cost is easy — it's whatever you spent on ads, tools, or agency fees for that campaign.
Revenue is where it gets messy. It lives inside your Google Analytics account, but GA4 doesn't hand you a clean "revenue by campaign" number on a silver platter. You have to know which report to open, how to set up conversion values correctly, and how to separate one channel's results from another's — and most people who aren't analytics specialists simply never get that far.
Why measuring marketing ROI feels harder than it should be
It's not that the math is hard. It's that reading the raw data requires knowing GA4 well enough to find the right report, interpret it correctly, and not accidentally mix up sessions with actual paying customers. Most business owners open Google Analytics, see a wall of numbers, and close the tab without an answer.
A simpler way to get the answer
This is exactly the gap Metriko was built to close. Connect your Google Analytics account once, and Metriko reads the same data you already have — and explains it back to you in plain, simple English: which channels are actually making you money, which ones aren't, and what your real marketing ROI looks like, without you needing to touch a single analytics report yourself.
No dashboards to decode. No formulas to remember. Just a straight answer to the question you actually asked: is this working or not?