Why ROAS matters
ROAS gives you a single number to compare campaigns, channels, and time periods. €1 in produced €4 in revenue → 4× ROAS. That simplicity is also its biggest trap: a 4× ROAS on a product with a 25% contribution margin barely covers ad spend, while a 4× ROAS on a 70% margin product is highly profitable.
Most teams report ROAS daily and use it for budget allocation. Done well, it surfaces real channel and campaign performance. Done poorly, it amplifies the platforms’ over-attribution and drives budget into channels that look efficient on paper but are actually free-riding on demand created elsewhere.
How ROAS is calculated
The base formula:
ROAS = Revenue from Ads ÷ Ad Spend
In practice, three flavours exist:
- In-platform ROAS, what Meta / Google / TikTok report. Each platform claims credit for conversions it touched, so summed across channels you often see 150%+ of actual revenue.
- Attributed ROAS, assigned via an attribution model that splits credit fairly between channels (last-click, multi-touch, data-driven).
- Blended ROAS, total revenue ÷ total ad spend. Channel-agnostic, can’t be over-claimed, but doesn’t tell you which channels deserve credit.
Use all three together: blended for the truth, attributed for allocation, in-platform for diagnosing in-channel optimization.
What a “good” ROAS looks like
ROAS targets are entirely a function of contribution margin and operating costs. Two rough rules:
- Break-even ROAS = 1 ÷ contribution margin. At 30% margin, break-even is ~3.33×.
- Target ROAS = break-even ÷ (1 − target operating margin). If you need a 20% operating margin, divide by 0.8.
A brand with thin margins might need 6×+ to be healthy. A high-margin DTC business can grow profitably at 2×.
Common mistakes
- Trusting in-platform ROAS as truth. It double-counts. Always compare against blended.
- Optimising for ROAS alone. A campaign with 8× ROAS and €200 in revenue contributes less than one with 3× ROAS and €5,000. Volume × margin matters more than the ratio.
- Comparing ROAS across attribution models. A last-click 4× ROAS is not the same number as a data-driven 4× ROAS. State the model.
FAQ about ROAS (Return on Ad Spend)
How is ROAS calculated?
ROAS equals revenue attributed to ads divided by ad spend, usually expressed as a multiple (e.g. 4.2×). The exact number depends heavily on the attribution model.
What is a good ROAS?
A good ROAS is anything above break-even ROAS, which equals 1 divided by your contribution margin. At 30% margin, break-even is about 3.33×. Add operating costs and the target rises.
Why is in-platform ROAS higher than blended ROAS?
In-platform ROAS counts every conversion the platform touched, even ones it did not actually cause. Sum the in-platform ROAS across Meta, Google, and TikTok and you usually exceed 150% of real revenue.