Competitor Ad Spend Benchmarker

Estimate a rival's ad spend from share-of-voice against your own.

$
%
Your impression share in the category.
%
From an auction-insights / SOV tool.
Est. total market spend
$222,222
Your spend ÷ your SOV
Est. competitor spend
$71,111
Market spend × their SOV
Spend gap
$31,111
Their spend − yours
They outspend you
1.78×
Relative ad weight

A rival at 32% SOV is likely spending ~$71,111/month, about $31,111 more than you. You don't have to match it; out-target and out-convert in the segments you can own instead of buying share everywhere.

Assumes spend maps roughly to share of voice within the same auction, a solid directional estimate, not a billing statement.

About this calculator

You can't see a competitor's ad account, but you can usually see their share of voice from an auction-insights or SOV tool, and since spend and share of voice move together within the same auction, that's enough to back into a credible estimate of what they're spending. This calculator does that math so you know roughly what you're up against before deciding whether to chase their budget or out-target it instead.

How to use it

  1. Enter your own monthly ad spend and your share of voice, your impression share within the category, from an auction-insights or SOV report.
  2. Enter the competitor's share of voice from the same source.
  3. Read the estimated total market spend, the competitor's estimated spend, the dollar gap between you, and how many times over they outspend you.

Methodology

The model assumes spend maps roughly proportionally to share of voice within the same auction. Total market spend is estimated as your spend divided by your share of voice: your spend ÷ (your SOV ÷ 100).

The competitor's estimated spend is that total market spend multiplied by their share of voice: total market spend × (competitor SOV ÷ 100).

The spend gap is competitor spend minus your spend, and the ratio (how many times over they outspend you) is competitor spend divided by your spend.

This is a directional estimate, not a billing statement. It assumes both of you are competing in a comparable auction with similar targeting, real-world differences in bidding strategy, targeting precision, and ad quality mean actual spend can diverge from this proportional estimate.

FAQ

How accurate is an estimate based on share of voice?

It's a reasonable directional signal, not a precise figure. Share of voice and spend are correlated within the same auction, but factors like Quality Score, targeting efficiency, and bid strategy mean two advertisers can buy different amounts of SOV for the same dollar. Treat the output as "roughly this much," not an exact number.

Do I need to match a competitor's spend if this shows a big gap?

No, and usually shouldn't try to. Out-targeting and out-converting in the segments where you have a real edge is more capital-efficient than trying to outbid a bigger budget everywhere. Use the gap to decide where to concentrate, not as pressure to match total spend.

Where do I get share-of-voice data for this calculator?

Auction insights reports in Google Ads and Microsoft Ads show impression share versus competitors directly. Third-party competitive intelligence tools (SEMrush, SpyFu, SimilarWeb and similar) provide broader SOV estimates across search and social if you need visibility beyond your own auction data.

What should I do with the "spend gap" number practically?

Use it to prioritize, not panic. A large gap in a segment where the competitor is heavily invested usually means they've found something working there; look instead for segments with lower competitor SOV where your budget goes further and you can build a defensible position before they notice.