Google Ads Wasted Spend Calculator
Enter numbers from your own Google Ads reports and see exactly how much spend is going to segments that miss your target CPA or ROAS, how much that costs per year, and what to fix first. No benchmarks, no guesses: every dollar in the result comes from your inputs.
Fill in the segments you can pull from your account. Leave any you can't check at zero. Rename or add your own.
How the calculation works
For each segment, the calculator compares what you spent with what that spend should have cost at your target:
| Mode | Formula per segment |
|---|---|
| Target CPA | waste = max(0, spend − conversions × target CPA) |
| Target ROAS | waste = max(0, spend − conversion value ÷ target ROAS) |
A segment with zero conversions counts as fully wasted for that period. A segment that beats your target counts as zero, never negative, so strong segments can't hide weak ones. The annualised figure multiplies the period total up to 12 months; treat it as a direction, not a forecast, because spend and performance shift through the year.
"Waste" here means spend you could have bought at your target efficiency. Some of it is worth keeping (brand-new campaigns still learning, or upper-funnel segments you judge on assisted conversions). The point is to see the number before deciding.
Where to find each number in Google Ads
| Segment | Report path | Filter |
|---|---|---|
| Non-converting search terms | Campaigns › Insights and reports › Search terms | Conversions = 0, sort by cost |
| Search Partners | Campaigns › Segment › Network (with search partners) | Row “Search partners” |
| Display and YouTube placements | Campaigns › Content › Where ads showed | Conversions = 0, cost above your target CPA |
| Locations outside your service area | Campaigns › Locations › Matched locations / user location | Locations you don't serve |
| Weak hours and days | Campaigns › Audiences, keywords and content › Ad schedule (or Insights › When and where) | Hours with CPA above target |
| Devices | Campaigns › Devices | Device rows with CPA or ROAS outside target |
What to do with the result
Start with the largest bar. Non-converting search terms are usually fixed with negative keywords and tighter match types; Search Partners with a single campaign setting; placements with exclusions; locations by switching to “Presence: people in or regularly in your targeted locations”; schedules and devices with bid adjustments where your bid strategy still allows them. Re-run the calculator on the next period's data to confirm the number went down.
For the full process, read our guide: Google Ads wasted spend: how to find and cut it. If you want a second pair of eyes on the account, our Google Ads audit tool covers structure and bidding.
FAQ
Does this tool use industry averages?
No. It only uses the numbers you type in. There are no hidden benchmarks or assumed waste rates.
Is my data stored?
No. Everything runs in your browser. Nothing is sent to a server.
Can a segment be counted twice?
Yes, if you enter overlapping slices (for example, search terms that also appear in a location you excluded). Use segments that don't overlap, or treat the total as an upper bound.
What period should I use?
Thirty days works for most accounts. Low-volume accounts should use 90 days so a single conversion doesn't swing a segment from “all waste” to “fine”.
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Built by Manish Chandwani, GrowwithBA. Last updated October 2026.