Google Ads ROAS Calculator
Enter your ad spend, conversion rate, and average order value. See your ROAS, break-even point, and cost per acquisition instantly.
Your Numbers
Your Results
How the calculator works
This calculator takes five inputs and returns five outputs. Here's what each formula does under the hood so you can sanity-check your numbers:
Conversions = Clicks × Conversion rate
Revenue = Conversions × AOV
ROAS = Revenue ÷ Spend
CPA = Spend ÷ Conversions
Break-even ROAS = 1 ÷ Profit margin
Net profit = (Revenue × Margin) − Spend
What is ROAS?
ROAS stands for Return on Ad Spend. It is attributed revenue divided by advertising spend. A ROAS of 4x means the platform attributes £4 in revenue for every £1 spent on ads. It is a useful media-efficiency ratio, but it does not include margin, fees, returns, overhead or whether the advertising caused the sale.
But here's the catch: ROAS measures revenue, not profit. A 4x ROAS sounds great, but if your profit margin is 20%, you're making £0.80 profit per £1 of spend — losing money. This is why break-even ROAS matters.
What is break-even ROAS?
Break-even ROAS is the minimum ROAS you need to not lose money after product costs. It's a function of your profit margin, calculated as:
Examples:
- 40% margin → break-even ROAS = 2.5x
- 30% margin → break-even ROAS = 3.33x
- 20% margin → break-even ROAS = 5.0x
- 10% margin → break-even ROAS = 10.0x
Anything below your break-even ROAS means you're losing money on every order acquired through ads. Many ecommerce advertisers obsess over ROAS targets without knowing their own break-even number — which is why unprofitable campaigns run for months.
What's a good ROAS?
There is no universal good ROAS. The minimum starts with contribution margin, then needs headroom for payment fees, fulfilment, returns, management cost, overhead and the profit the business expects. The table below is arithmetic, not an industry benchmark: it shows the ROAS required to break even on product margin and to retain 20p or 40p for every £1 of ad spend before other costs.
| Contribution margin | Break-even ROAS | ROAS for £0.20 headroom | ROAS for £0.40 headroom |
|---|---|---|---|
| 70% | 1.43x | 1.71x | 2.00x |
| 50% | 2.00x | 2.40x | 2.80x |
| 40% | 2.50x | 3.00x | 3.50x |
| 30% | 3.33x | 4.00x | 4.67x |
| 20% | 5.00x | 6.00x | 7.00x |
How to improve your ROAS
If the calculator above shows you're below break-even, you have three levers to pull:
- Lower your CPA — better keyword targeting, negative keywords, improved Quality Score, sharper audience signals. Usually the first thing to tackle because it compounds across every campaign.
- Raise your conversion rate — landing page work (see our guide to high-converting ecommerce landing pages), checkout friction reduction, trust signals. Big leverage on ROAS because it multiplies the numerator without touching the denominator.
- Raise your AOV — bundling, upsells at checkout, tiered pricing. Often the fastest win for established stores.
Full walkthrough: How to Calculate & Improve Your Google Ads ROAS.
Related tool
If your ROAS is below break-even, the next question is where the waste is coming from. Use the Google Ads Waste Calculator to break it down by unprofitable CPA, CPC premium, and landing page gap.
Frequently Asked Questions
ROAS Below Break-Even?
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