# ROAS

> What ROAS means, how to calculate return on ad spend, why the revenue side decides its accuracy, and how MIRA FIVE shows ROAS for Google Ads.

URL: https://mirafive.io/glossary/roas  
Updated: 2026-09-26

ROAS, return on ad spend, is the revenue a campaign brought divided by what it cost: €4 back for every €1 spent is a ROAS of 4.

ROAS divides the revenue attributed to advertising by the ad spend that produced it. A campaign that cost €1,000 and brought €4,000 in revenue has a ROAS of 4, often written as 400%. Whether that is good depends on your margin: a business with a 25% margin needs a ROAS above 4 before the ad earns money.

The spend side is exact; the revenue side is where ROAS goes wrong. Ad platforms report the conversions they can see through their own tracking and estimate some of the rest. Measuring revenue in your own analytics, joined to the ad click, gives a figure you can check against real [buyers](https://mirafive.io/glossary/buyer).

## In MIRA FIVE

The Google Ads connection imports daily spend, clicks, impressions and conversions per campaign and joins them to visits by `utm_campaign` or gclid. Acquisition then shows cost per visit, cost per buyer and ROAS for each campaign. Campaigns that spend without tags get a diagnosis, so untagged spend is visible rather than lost. Meta Ads is next.

## Read next

### Guides on this

### [How to see your Google Ads cost per buyer](https://mirafive.io/learn/google-ads-cost-per-buyer)

Google Ads cost per buyer divides spend by the people who paid, not by the conversions Google counts. How MIRA FIVE joins spend to visits and shows ROAS.

### [How to calculate ROAS and cost per buyer](https://mirafive.io/learn/how-to-calculate-roas)

How to calculate ROAS and cost per buyer from ad spend, revenue and buyers, find the break-even ROAS for your margin, and read both with one worked example.

### Related terms

- [Click ID](https://mirafive.io/glossary/click-id)
- [UTM parameters](https://mirafive.io/glossary/utm-parameters)
- [Buyer](https://mirafive.io/glossary/buyer)
- [Channel](https://mirafive.io/glossary/channel)

[All terms](https://mirafive.io/glossary)

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