Google Ads ROAS & Budget Waste Calculator
Model ecommerce or lead-generation economics to identify where CPC, conversion efficiency or commercial inputs are putting pressure on performance.
Campaign spend
Total Google Ads spend this month
Average cost per click from your account
% of clicks that complete a purchase
Product economics
Revenue minus COGS, as a percentage of revenue
Optional: from Google Ads
Conv. value ÷ cost from your Google Ads dashboard
Your goal: leave blank if not set
Fill in the inputs on the left to see your diagnostic results.
Practical guidance
About this tool
This calculator models whether current Google Ads economics appear sustainable and identifies which entered commercial variable places the most pressure on performance. It supports separate ecommerce and lead-generation calculations.
It does not connect to or inspect a Google Ads account. The output depends entirely on the manual inputs and the implemented decision rules, so use it as a diagnostic starting point rather than evidence of a specific account problem.
Want a second opinion on your Google Ads account?
I can review spend allocation, search terms, conversion tracking, bidding, landing pages and profitability to show where performance is being lost and what to address first.
How to use the Google Ads calculator
- 1Choose Ecommerce when conversions are purchases, or Lead Generation when revenue depends on leads becoming sales.
- 2Enter campaign spend and average CPC for the same reporting period.
- 3Complete the conversion and commercial inputs required by the selected mode.
- 4Add the optional current ROAS, target ROAS or target CPA where available.
- 5Review the break-even signal, efficiency metrics and fixed what-if scenarios.
- 6Use the ranked diagnosis to decide what should be verified in the actual account first.
Inputs used by each mode
Ecommerce
The ecommerce model requires monthly ad spend, CPC, website purchase conversion rate, average order value and gross margin. It estimates clicks, orders, revenue, gross profit, CPA, break-even ROAS, maximum CPC and the conversion rate or AOV required to break even.
- Current ROAS is optional. When supplied, it replaces the calculated ROAS in the displayed Current ROAS card.
- Target ROAS is collected for reference in the current interface, but it does not alter the profitability calculation or ranked diagnosis.
Lead generation
The lead-generation model requires monthly ad spend, CPC, lead conversion rate, lead-to-sale close rate, average deal value and gross margin. It estimates clicks, leads, closed sales, revenue, gross profit, cost per lead, cost per sale, break-even cost per sale, maximum CPC and required lead conversion rate.
- Target CPA is optional and contributes a diagnosis when modeled cost per sale is more than 20% above the entered target.
How the diagnosis works
For context, Google Ads defines conversion value per cost as conversion value divided by cost. See Google's explanation of conversion reporting.
The calculator first estimates outcomes from spend, CPC and the relevant conversion rates. It then compares estimated gross profit with ad spend and ranks triggered rules around CPC affordability, conversion efficiency, margin, order or deal value, close rate and optional targets.
- Ecommerce what-if scenarios model a 25% conversion-rate increase, 20% CPC reduction and 20% AOV increase.
- Lead-generation scenarios model a 25% lead-conversion increase, 20% CPC reduction and 25% close-rate increase.
- The scenarios change one variable at a time. They do not predict what will happen in the live auction or sales process.
Common sources of Google Ads budget waste
The calculator does not detect the account-level issues below. They are practical areas to investigate when the modeled economics indicate pressure.
- Irrelevant search terms or weak match-type and negative-keyword control.
- Conversion tracking that counts low-value actions or omits meaningful conversion value.
- CPC that is too high relative to landing-page conversion and commercial value.
- Campaigns optimising towards the wrong conversion action or unreliable value data.
- Budget allocated without regard to margin, lead quality or closed revenue.
- Landing pages, creative or offers that do not match the query and audience intent.
- Bidding targets that restrict useful volume or ignore the economics represented by the business.
What this calculator cannot see
- Search terms, match types, campaign structure and bidding history.
- Conversion actions, attribution settings and offline conversion imports.
- Lead quality, sales follow-up and actual close reasons.
- Audience, device, geographic and time-based performance.
- Landing-page experience, creative quality and offer strength.
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Frequently Asked Questions
Does this calculator inspect my Google Ads account?
No. It does not connect to Google Ads or read campaigns, search terms, conversions or bidding data. It models outcomes from the values you enter.
How does the ecommerce mode assess break-even performance?
It estimates clicks from spend and CPC, orders from clicks and conversion rate, revenue from orders and AOV, and gross profit from revenue and margin. Estimated gross profit is then compared with ad spend.
How does lead-generation mode value a lead?
It estimates leads from click-to-lead conversion rate, sales from the entered close rate, and gross profit from deal value and margin. This means lead volume alone is not treated as the final commercial result.
Is ROAS the same as profit?
No. ROAS compares conversion value or revenue with ad spend. Profitability also depends on margin and other costs. A campaign can report a positive ROAS and still be unprofitable under the business's actual economics.