How to Estimate a Competitor's Google Ads Budget with Auction Insights
Can you find out how much a competitor spends on Google Ads? Not exactly. Google never shows another advertiser's budget, bids or spend, and no tool can read them from outside their account.
What you can do is estimate a rough range, for the keywords you both bid on, from data you already have: your own impressions, clicks and cost per click, plus the competitor's impression share from the Auction insights report. This guide shows the formula, a full worked example, and where the estimate goes wrong.
The short answer
- Work out how many impressions were available in your auctions: your impressions ÷ your impression share.
- Multiply that by the competitor's impression share to get their approximate impressions.
- Multiply by a low, realistic and high CTR to get a range of clicks.
- Multiply the clicks by a CPC (start with your own) to get a spend range.
The result is what the competitor might spend on your keywords in that period. It is not their total budget.
What data does Google Ads actually give you?
From your own account, you know everything about yourself: impressions, clicks, CTR, average CPC, cost and search impression share.
About competitors, the Auction insights report gives you only visibility metrics, for the auctions you also took part in:
- Impression share: how often they showed, out of the auctions they were eligible for;
- Overlap rate: how often their ad showed when yours did;
- Position above rate: how often their ad ranked above yours;
- Top of page rate and Absolute top of page rate;
- Outranking share: how often you ranked above them, or showed when they did not.
No bids, no budgets, no clicks and no keywords. Shares under 10% show only as "< 10%". So any spend figure has to be built from impression share plus assumptions. (For what each metric means and how to read it when performance drops, see this auction insights section.)
Pick the right level: campaign, ad group or keyword
Auction insights can be opened at campaign, ad group and keyword level. Use the level that matches the question:
- One keyword, for example your most expensive one: open auction insights for that keyword, and use that keyword's impressions and impression share.
- A group of related keywords: use the ad group's report and the ad group's numbers.
- Everything in a campaign: use the campaign's report and totals.
Always take your own numbers and the competitor's numbers from the same level and the same date range. Mixing a campaign's impressions with a keyword's impression shares gives nonsense.
How to estimate a competitor's spend, step by step
Here is the method with an example. Say you run a search campaign for a home cleaning service, and for the last 30 days at campaign level you have:
| Your data (last 30 days) | Value |
|---|---|
| Impressions | 12,000 |
| Search impression share | 30% |
| CTR | 5% (600 clicks) |
| Average CPC | $2.50 |
| Cost | $1,500 |
Auction insights for the same campaign and dates shows three competitors:
| Competitor | Impression share | Position above rate | Top of page rate |
|---|---|---|---|
| Competitor A | 55% | 60% | 85% |
| Competitor B | 20% | 25% | 50% |
| Competitor C | < 10% | 10% | 30% |
Step 1: Estimate the total impressions available
Your impression share says you got 30% of the impressions you were eligible for. So the whole pool was about:
12,000 ÷ 0.30 = 40,000 impressions
Step 2: Estimate each competitor's impressions
Multiply the pool by each competitor's impression share. For "< 10%", pick a value; 5% is a reasonable middle.
- Competitor A: 40,000 × 55% = 22,000
- Competitor B: 40,000 × 20% = 8,000
- Competitor C: 40,000 × 5% = 2,000
Step 3: Turn impressions into clicks with three CTRs
You don't know their CTR, so use a range. Your own CTR (5%) is a good realistic middle. Pick a low and high around it, and lean higher for competitors that are usually at the top of the page (Competitor A shows at the top 85% of the time, so its CTR is likely above yours).
Using 3%, 5% and 8%:
| Competitor | Low (3%) | Realistic (5%) | High (8%) |
|---|---|---|---|
| A (22,000 impressions) | 660 clicks | 1,100 clicks | 1,760 clicks |
| B (8,000 impressions) | 240 clicks | 400 clicks | 640 clicks |
| C (2,000 impressions) | 60 clicks | 100 clicks | 160 clicks |
Step 4: Turn clicks into spend
Multiply the clicks by a CPC. Start with your own $2.50. A competitor who often ranks above you is probably paying around your CPC or more, so you can also run their numbers at a slightly higher CPC.
| Competitor | Low | Realistic | High |
|---|---|---|---|
| A | $1,650 | $2,750 | $4,400 |
| B | $600 | $1,000 | $1,600 |
| C | $150 | $250 | $400 |
So, on the keywords in this campaign, Competitor A probably spends somewhere around $1,650 to $4,400 a month, against your $1,500, with about $2,750 as the most likely figure. Competitor B spends less than you, and Competitor C very little.
Why is this only a rough estimate?
Keep these limits in mind before acting on the numbers:
- It only covers your keywords. A competitor may run 100 keywords and share 10 with you. You see only those 10. Their real budget can be many times larger.
- CTR and CPC are guesses. A better ad or offer gives them a higher CTR; a better Quality Score can give them a lower CPC for the same position. Either can move the estimate a lot.
- Impression share is itself an estimate. Google calculates the eligible impressions, and it does not include Search partners.
- Small competitors are blurred. Everything under 10% shows as "< 10%", and advertisers below Google's threshold may not appear at all.
- Match types and locations differ. A competitor's ad can match different searches, or target a wider area, than yours. Auction insights only counts the auctions you entered.
- Budgets change. Seasonal advertisers spend in bursts. A 30-day window can catch a peak or a quiet month.
Treat the result as a direction ("they spend about twice what we do on these keywords"), not an exact figure.
Are there other ways to see competitor ad spend?
- Third-party tools such as Semrush and SpyFu show estimated PPC budgets for a domain. They model the figures from search volume, estimated CPCs and positions; they do not see real accounts. SpyFu suggests calibrating them by comparing the tool's estimate of your domain with your real spend. Practitioners often report big differences from real spend, especially for small local advertisers.
- Google Ads Transparency Center shows the ads an advertiser runs, by region and format, but not how much they spend, except for election ads in some regions.
- Keyword Planner gives the top-of-page bid range for each keyword, which is a useful check on the CPC you assume.
None of these is better than the auction insights method for your own keywords, because your data comes from the actual auctions you compete in.
What should you do with the estimate?
Knowing a competitor spends more than you does not mean you should match them. Use it to decide where to compete:
- If a big spender dominates a keyword (high impression share, high position above rate), check whether winning it is worth the cost. Work out your cost per lead first; the Google Ads cost calculator helps.
- Look for keywords, locations, hours or days where they show less, and shift budget there.
- Compete on the ad and the offer, not just the bid. A higher CTR and better landing page lower your cost for the same position.
- Watch your Search lost IS (budget) and (rank) columns. Losing to budget means more money would buy more impressions; losing to rank means you need a better Ad Rank, not just a bigger budget.
Frequently asked questions
Can I see a competitor's exact Google Ads budget?
No. Google does not share any advertiser's budget, bids or spend with others. You can only estimate it from auction insights and your own data, or from third-party tools that also estimate.
What formula estimates competitor spend?
(Your impressions ÷ your impression share) × competitor impression share × an assumed CTR × an assumed CPC. Run it with low, realistic and high CTRs to get a range.
Why does auction insights show "< 10%"?
Google shows impression shares below 10% as "< 10%" instead of an exact number. For an estimate, use a value between 1% and 9%, such as 5%, and treat that competitor's result as very rough.
Does this estimate show the competitor's total budget?
No. It covers only the auctions you both entered, so only the keywords, locations and times you share. Their total budget can be much higher.
How accurate are tools like Semrush or SpyFu for ad spend?
They are modelled estimates, not real data. They can show which competitors advertise and roughly how much compared with each other, but their dollar figures for a single advertiser can be far off. Compare the tool's estimate for your own site with your real spend to see how far off it is in your industry.