You are trying to plan your marketing spend, but you are flying blind. How much is “enough” to compete? If you underestimate your competitor’s budget, you will be drowned out. If you overestimate, you might be scared to enter the market.

To accurately check a competitor’s Google Ads budget, you should use the “Reverse Math Formula” (Estimated Traffic × Average CPC), analyze the “Impression Share” metric in Google’s Auction Insights to see if they are budget-capped, and validate these numbers using intelligence tools like Semrush or SpyFu. This triangulation method provides a realistic spending range rather than a single, often inaccurate number.

I will break down exactly how to perform these three calculation methods step-by-step.

Method 1: The “Reverse Math” Manual Calculation

Most blog posts just tell you to buy software. But I prefer to do the math myself first because it often reveals the “floor” of their spending. You can do this using free data.

How Do I Use the Budget Formula?

I use a simple formula: Total Monthly Clicks × Average Cost Per Click (CPC) = Estimated Budget. First, I use the Google Keyword Planner to find the top 5-10 keywords my competitor is definitely bidding on. I look at the “Avg. Monthly Searches” and the “Top of page bid.” For example, if they target “CRM Software” (10,000 searches) and “Best CRM” (5,000 searches), the total pool is 15,000 searches. I assume a standard industry Click-Through Rate (CTR), typically around 3% for search ads.

• 15,000 searches × 3% CTR = 450 Clicks.

• If the Average CPC is $10.

• 450 Clicks × $10 = $4,500/month just for these keywords. This gives me a baseline. I repeat this for their top 20 keywords to build a “minimum viable budget” estimate.

Why Is Variable CPC Important?

I always calculate a “High” and “Low” scenario. In Google Keyword Planner, I use the “Low range” bid for my conservative estimate and the “High range” bid for the aggressive estimate. Competitors with low-quality scores pay the “High” price. Competitors with great ads pay the “Low” price. This gives me a budget range (e.g., between $4,000 and $8,000), which is far more useful for planning than a single guess.

Method 2: The “Auction Insights” Impression Share Hack

This is the most accurate method that relies on actual Google data, not third-party scrapes. It tells you if a competitor is running out of money.

What Does “Impression Share” Reveal About Budget?

Inside my Google Ads account, I go to the Auction Insights report. I look at the “Search Impression Share” column for my competitor.

• If a competitor has <100% Impression Share, they are missing out on impressions.

• I then check the “Search Lost IS (budget)” column (you may need to add this column).

• If this number is high (e.g., 50%), it means they are running out of money. They are capturing only half the traffic they could because their budget is capped.

• If this number is 0%, it means they have an unlimited budget for that keyword set.

How Do I Calculate Their Total Potential Spend?

If I know my own budget and impression share, I can estimate theirs.

• My Math: If I spend $1,000 to get a 10% Impression Share, the “Total Addressable Market” cost is roughly $10,000 (1,000 / 0.10).

• If my competitor has a 50% Impression Share, they are likely spending around $5,000 (50% of the total market cost). This “Rule of Proportions” is incredibly accurate because it is based on the real auctions we are both participating in.

Method 3: Third-Party Intelligence Tools

Tools are faster, but they have blind spots. I use them to see the trend rather than the exact dollar amount.

Which Tools Are Most Reliable?

I rely on Semrush and SpyFu. These tools scan search results pages millions of times to see who is appearing.

• SpyFu: I find it excellent for historical data. It can tell me, “This competitor doubled their budget last November.” This helps me predict seasonality.

• Semrush: I use the “Advertising Research” tab. It breaks down the budget by country and device. This is critical. I often find that a competitor looks huge, but 80% of their budget is spent on cheap mobile traffic that doesn’t convert well.

What Are the Common Errors in Tool Estimates?

I never trust these numbers blindly. These tools often underestimate budget because they cannot see “Broad Match” keywords or branded searches properly. Conversely, they can overestimate if they assume a competitor is paying full price for every click, when in reality, the competitor might have a high Quality Score and pay less. I treat the tool’s number as an index. If the tool says they spend $10k, the real number is likely between $8k and $15k.

How to Beat a Competitor With a Bigger Budget?

Once I know their budget, the goal isn’t just to match it. It is to outsmart it.

Why Does “Creative Quality” Beat “Wallet Size”?

Google Ads is an auction, but the highest bidder doesn’t always win. Google prioritizes the Quality Score. If my ad has a higher expected CTR, I can pay less than my competitor for the same spot. I have seen competitors spending $50,000/month on generic, boring ads. I can often beat them with a $20,000 budget simply by having better creatives. This is where I stop fighting a bidding war and start fighting a “creative war.”

How Can I Lower My Costs to compete?

I focus on increasing engagement. Instead of standard text ads or static banners, I use interactive ads. Platforms like Gamewheel allow me to create playable ads that users actually enjoy clicking.

• The Logic: Higher Engagement → Higher CTR → Higher Quality Score → Lower Cost Per Click. By using better ad formats, I effectively stretch my budget. If I pay $2 per click while my competitor pays $4 (because their ads are boring), my $10,000 budget is worth as much as their $20,000 budget.

Conclusion

You don’t need to outspend your competitors to beat them. By calculating their budget using these three methods, you can find their financial limit, and then use superior creative strategies to outmaneuver them.