How do you calculate ROAS?

Divide the revenue your ads generated by what you spent on them. $12,000 from $4,000 of spend is 3.00x. Use the same dates and the same campaigns for both numbers, or the ratio means nothing.

Any ROAS above your break-even ROAS, with a buffer. At a 40% contribution margin break-even is 2.50x, so 3.00x is profitable; at 30% it is not. The often-quoted 4x is simply break-even for a product with a 25% margin.

How do I write ROAS as a percentage?

Multiply the ratio by 100. 3.00x is 300%. Google Ads target ROAS takes the percentage; Meta's ROAS goal takes the ratio.

Is ROAS the same as ROI?

No. ROAS divides revenue by ad spend. ROI divides the profit left after costs and ads by ad spend. The example campaign has a ROAS of 3.00x but returns $800 on $4,000, an ROI of 20%.

What is the difference between ROAS and MER?

ROAS uses the revenue a platform attributes to one campaign. MER, marketing efficiency ratio, divides all revenue by all ad spend for a period. ROAS tells you which campaign to cut; MER tells you whether advertising as a whole is paying off.

ROAS Calculator

Your return on ad spend, and whether it actually made you money.

Revenue from ads

What Ads Manager or Google Ads reports, for the same campaign and dates as the spend.

Ad spend

Contribution margin

Share of the order left after every cost except advertising.

Your ROAS

3.00x

As a percentage (Google Ads): 300%
Your break-even ROAS: 2.50x
Contribution profit after ads: $800.00

3.00x clears your 2.50x break-even. These ads are paying for themselves.

Tariffs change. Your floor changes with them.

We write when a rate actually moves. Not on a schedule, not otherwise.

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What ROAS is

ROAS, return on ad spend, is the revenue your ads brought in for every dollar they cost.

ROAS = revenue from ads ÷ ad spend

$12,000 of revenue on $4,000 of spend is a ROAS of 3.00x, which Google Ads writes as 300%. Same number, two notations.

On its own, ROAS does not tell you whether you made money. It counts revenue, and revenue is not profit: the product, shipping, fees and returns all come out of it before the ads do. That is what the margin input is for. It turns your ROAS into a yes or no.

The three inputs

Revenue from ads: What the ad platform attributes to the campaign, over the same dates as the spend. Platforms tend to over-count, so this is an upper bound. For revenue no platform claims, use the MER calculator instead.
Ad spend: What you paid the platform for those dates. Agency fees and creative costs are not ad spend here; they belong in your overhead.
Contribution margin: The share of each sale left after every cost except advertising. If you do not know it, the break-even ROAS calculator builds it from price, landed cost and fees. Break-even ROAS is 1 divided by this number.

A worked example

A campaign spends $4,000 and the platform reports $12,000 of sales: 3.00x. The product keeps 40% of each sale after costs, so break-even is 1 ÷ 0.4 = 2.50x. The campaign clears it. Of the $12,000, $4,800 is contribution, the ads cost $4,000, and $800 is left.

Now keep the campaign exactly as it is and let the margin drop to 30%, which is what a new tariff or a marketplace fee can do. The ROAS is still 3.00x, but break-even rises to 3.33x and the same campaign now loses $400. Nothing in the ad account changed. That is why a ROAS number means nothing until you hold it against your own floor.

Is your ROAS good?

Published figures for what ecommerce campaigns return, pulled from the reports cited below. They disagree with each other by more than 2×, which tells you how much weight to give them:

Channel	Published figures
TikTok Ads	1.4x – 4.0x
Meta Ads	1.9x – 4.0x
Google Search & Shopping	3.5x – 8.0x

A good ROAS is one that sits above your break-even with room to spare, whatever the averages say. The guide to what a good ROAS is works through that by margin and by channel, and the break-even ROAS chart shows the floor for every margin and duty rate.

Next steps

Break-Even ROAS Calculator

The ROAS below which every sale loses money.

Target ROAS Calculator

From break-even to the buffer you actually bid at.

MER Calculator

Marketing efficiency ratio across every channel.

What Is a Good ROAS?

It depends on your margin. Here is by how much.

Questions

How do you calculate ROAS?: Divide the revenue your ads generated by what you spent on them. $12,000 from $4,000 of spend is 3.00x. Use the same dates and the same campaigns for both numbers, or the ratio means nothing.
What is a good ROAS?: Any ROAS above your break-even ROAS, with a buffer. At a 40% contribution margin break-even is 2.50x, so 3.00x is profitable; at 30% it is not. The often-quoted 4x is simply break-even for a product with a 25% margin.
How do I write ROAS as a percentage?: Multiply the ratio by 100. 3.00x is 300%. Google Ads target ROAS takes the percentage; Meta's ROAS goal takes the ratio.
Is ROAS the same as ROI?: No. ROAS divides revenue by ad spend. ROI divides the profit left after costs and ads by ad spend. The example campaign has a ROAS of 3.00x but returns $800 on $4,000, an ROI of 20%.
What is the difference between ROAS and MER?: ROAS uses the revenue a platform attributes to one campaign. MER, marketing efficiency ratio, divides all revenue by all ad spend for a period. ROAS tells you which campaign to cut; MER tells you whether advertising as a whole is paying off.

Sources and last update

Last verified 2026-08-22.

Figures here are planning estimates. Duty applies per 10-digit HTS code and platform fees change without much notice — check your own broker and your own seller account before committing spend. Full workings on the methodology page.