Estimate competitor Google Ads spend

Your boss forwards you a screenshot of a rival sitting above you on all three of your money keywords and asks the question every search buyer dreads: "How much are they spending?" You open a couple of tools. SpyFu says one number, Semrush says something 40% different, and a third says the competitor barely advertises at all. None of them agree, and now you have to walk back into that meeting with something.

Here is the honest version of that answer, and the method that gets you to it.

The takeaways

• Google publishes zero competitor spend data, so every dollar figure you see is a model, not a fact. Treat all of them as directional.
• Your own Auction Insights is the only spend signal that comes straight from Google's auctions, but it hides any competitor under 10% impression share and only covers the hours your own budget was live.
• Ratios survive where absolute numbers don't: "Competitor A shows up in roughly 4x as many of our auctions as Competitor B" is defensible. "Competitor A spends $47,000 a month" is a guess wearing a suit.

Can you actually see a competitor's Google Ads budget?

No. Google does not share spend, bids, budgets, or click volume for any advertiser but you. The Ads Transparency Center shows you a rival's live ads, headlines, and extensions, but no money. Auction Insights shows how often you collide in the same auctions, but no money. Every absolute spend figure from a third-party tool is a model built on estimated clicks times an estimated cost-per-click, and both inputs are guesses.

That does not make the question pointless. It means you answer it in ranges and ratios, and you stop pretending the decimal places mean anything.

What does the Clicks times CPC formula actually give you?

It gives you a rough ceiling on what a rival could be spending, never the budget itself. The standard tool method is Estimated Monthly Clicks multiplied by Average CPC, and it falls apart in three predictable places.

First, the click estimate assumes you know a competitor's impression volume and click-through rate, and you know neither. Second, the CPC you plug in is your CPC, shaped by your Quality Score, not theirs. A competitor with a stronger landing page pays less per click for the same position, so your formula overstates their spend. Third, the formula treats one month as steady state and ignores that most accounts pulse: heavy in Q4, throttled in summer, paused during a stockout.

Use the formula to sanity-check an order of magnitude. If a tool tells you a local plumber spends six figures a month on Search, the formula is how you catch that it is nonsense.

What can your own Auction Insights honestly tell you?

More than any paid tool, because it is the only source that reports actual auction behaviour straight from Google. Pull the Auction Insights report on your own campaigns and read the impression share column for each competitor: it is the percentage of eligible auctions where their ad appeared. A rival holding 15 to 20%+ impression share on your core terms is committing real budget there. One flickering at 11% is dabbling.

Three caveats keep this honest. Google does not report any competitor sitting below 10% impression share, so a long tail of smaller spenders is simply invisible. The report only covers auctions you were present for, so if your budget runs dry at 2pm, you are blind to every evening auction a competitor might dominate. And impression share is aggregated across your geo and device targeting, so a competitor showing 50% overall might be at 95% in three cities and absent everywhere else. Read the trend, not the decimal.

Does ad longevity tell you anything about commitment?

Yes, and it is the signal most spend estimates ignore. An ad that has been running continuously for a month is a different animal from one that launched yesterday. Advertisers kill losers fast, so durability is a revealed preference: the longer a creative survives, the more confident you can be that it is paying its own way, which usually means real money is flowing behind it.

This is where the Google Ads Transparency Center earns its place next to Auction Insights. It will not tell you a budget, but it shows you which of a competitor's ads are still live and how many distinct creatives they are running. This is exactly the durability angle Adscalr leans on: it reads the same public ad libraries daily and flags a competitor ad that is still running after 30 or more days as a durable winner, the kind of commitment signal a one-week snapshot would miss. Ad volume and longevity together give you a "are they serious here" read that no spend figure can.

So what number do you give your boss?

Give a direction and a confidence level. Skip the fake precision. Something like: "On our three core keywords, Competitor A holds 18 to 22% impression share and has run the same offer for six weeks, so they are clearly committed and likely outspending us there. Two smaller rivals are below Google's 10% reporting line, so they are noise for now. I would not trust any specific dollar figure, but the relative picture is solid."

That answer is more useful than an invented monthly total, because it is built on data you can defend and it points at an action: where to hold your ground and where a rival has left a lane open. Estimating competitor spend on Google is less about finding the right number and more about reading commitment honestly, which is the whole job of competitor intelligence. If you also want the spend picture across social ad libraries, the same honest-limits logic applies when you estimate competitor ad spend more broadly.