What is ROAS and how to calculate it, with real examples
ROAS (Return on Ad Spend) measures how much revenue you generate for every leu spent on ads, calculated as ad revenue divided by ad spend. Spend 1,000 RON and generate 4,000 RON and your ROAS is 4.
What ROAS Means
ROAS (Return on Ad Spend) measures how many units of revenue you generate for every unit spent on advertising. Formula, revenue from ads divided by ad spend.
Example, if you spend €200 on Google Ads and generate €800 in sales, your ROAS is 4. For every €1 invested, you got €4 back.
ROAS doesn't tell you if you're profitable. It tells you how efficient your ads are at generating revenue. Profitability depends on your margin.
How to Calculate ROAS
Formula, ROAS = Revenue from ads / Ad spend
Both Google Ads and Meta Ads calculate it automatically in the dashboard. On Google it appears as "Conversion value / cost". On Meta, as "Purchase ROAS".
What's a Good ROAS
There's no universally "good" ROAS - it depends entirely on your gross margin. Break-even ROAS formula, 1 / gross margin. A store with 25% margin needs ROAS 4 just to cover ad costs, before operational expenses.
From Romanian accounts we manage, eCommerce fashion 4-8, home & decor 3-6, electronics 2-4, local services 5-15.
When ROAS Is Misleading
Three situations where a high ROAS is deceptive, incorrect attribution (both Meta and Google claim the same conversion), ROAS calculated without returns/platform fees/fulfilment costs, and short-term ROAS that ignores customer lifetime value.
Why Improving ROAS Is Harder Than It Looks
The directions are logical, reduce cost per acquisition or increase average order value. The problem is that each involves decisions that interact with each other. Reduce budget on low-ROAS campaigns, and the algorithm loses the data it needs to optimize. Increase average order value through bundles, and you change conversion rate. Refine audiences, but a smaller audience can exhaust budget inefficiently.
ROAS doesn't improve through a single isolated change. It improves when multiple variables - bid strategy, structure, creative, product page, offer - align simultaneously. Identifying which variable is blocking ROAS and in what order to intervene is exactly where most accounts waste entire months.
Frequently asked questions
What is ROAS and how is it calculated?
ROAS (Return on Ad Spend) is the ratio between revenue generated and the amount spent on advertising. Formula, ROAS = Revenue from ads / Ad cost. A ROAS of 4 means for every 100 RON spent you generated 400 RON in revenue. It's the primary metric for eCommerce.
What ROAS should I target?
Target ROAS depends on your gross margin. If gross margin is 40%, you need at minimum ROAS 2.5 to cover advertising cost (100/40 = 2.5). But this is the zero-profit threshold - for a healthy business, target ROAS should be 1.5-2x above break-even. Always calculate based on your real margin, not industry benchmarks.
What is the difference between ROAS and ROI?
ROAS measures advertising efficiency (revenue/ad spend). ROI (Return on Investment) measures total profitability of an investment, including all costs, production, delivery, salaries - not just advertising. A ROAS of 5 can be unsustainable if gross margin is 15% and operational costs are high. Both matter, but for campaign optimization, ROAS is the operational metric.
Does a low ROAS always mean campaigns aren't working?
Not necessarily. An apparently low ROAS can be profitable if customer LTV is high and repurchase is frequent. For example, if a customer acquired at ROAS 1.5 buys 4 times per year, LTV ROAS can be 6+. Judge ROAS in the context of customer lifecycle, not just the first transaction.
How does attribution affect ROAS calculation?
The attribution model chosen in Google Ads or Meta dramatically affects reported ROAS. Last Click attributes the entire conversion to the last clicked ad; Data-Driven distributes fractionally across multiple touchpoints. ROAS reported in ad platforms is always more optimistic than real ROAS, due to multiply-attributed conversions. Compare with GA4 or your eCommerce platform data for a realistic picture.
At DAFE Digital we optimise campaigns on real ROAS, not estimates. Correct tracking, clear attribution, data-driven decisions.
ROAS is a simple metric with a complex problem, it depends entirely on how correct the tracking is. We configure conversion and attribution correctly so reported ROAS reflects actual revenue.
Adela Mincea
Performance Marketer · Fondatoare DAFE Digital · Formator ANC
Adela is a Performance Marketer with 10+ years of paid media across Europe, the US and Asia. She founded DAFE Digital in 2023 after agency roles in London and Hong Kong, in-house work inside client organisations, and independent consulting across 27+ industries.
