TL;DR
- The formula: Your count ÷ total count × 100. Your count is in the total.
- By channel: Spend, impressions, clicks, searches or mentions. Never blend them.
- A sheet to copy: Paste it, done.
- In AI answers: Ahrefs was named by all 5 engines and still had 16.1%.
- ESOV: Share of voice minus share of market.
Does AI name your brand? Check your site.
Share of voice is one division.
Your count. Divided by everyone's count. Times 100.
The math is easy. The trap is the total.
Add one competitor to your list and 20% becomes 15%. Nothing changed in the market. Only your list did.
Below: the formula for every channel, a sheet you can paste, a real AI example, and ESOV.
First, Understand the Basic Formula
Share of voice = (your count ÷ total count) × 100
Example. You got 1,500 mentions last month. Three competitors got 2,700, 2,100 and 1,200.
- Total: 1,500 + 2,700 + 2,100 + 1,200 = 7,500
- Your share: 1,500 ÷ 7,500 × 100 = 20%
Three rules:
- You're in the total. Divide by competitors only and you get 25%. Wrong.
- Same unit on both sides. Mentions over mentions. Same month. Same country.
- All shares add to 100%. Here: 20 + 36 + 28 + 16.
The formula by channel
Same division. Different count.
| Channel | You count | Where to get it |
|---|---|---|
| Ads | Ad spend | Your invoices. Competitors are an estimate |
| Paid search | Impressions | Google Ads |
| SEO | Estimated clicks | Search Console plus a rank tracker |
| Share of search | Brand searches | Google Trends |
| Social, PR | Mentions | Counted by hand |
| AI answers | Mentions in answers | The engines, logged by hand |
| Local | Grid points in the top 3 | Local Falcon |
The ad spend version is the original. Nielsen defines it as your media spend as a share of all media spend.
More on that: share of voice in advertising.
Stop Tracking Everything - Define Your Battlefield First
The total decides your answer. So fix four things first:
- The brands. Who's in the total?
- The channel. One per number.
- The period. Same length every time.
- The keywords or prompts.
Watch what happens when you add one brand:
20% became 15%. You didn't lose anything.
So write your list down. Freeze it.
I'd pick 3 to 5 competitors. The ones you actually lose deals to. Fifteen brands makes every share tiny.
And always report the scope: "20% social SOV vs A, B and C, September 2026."
How to Calculate SOV Manually (Without Fancy Tools)
You need a spreadsheet. That's all.
Build the calculator in a spreadsheet
Paste this into cell A1. Google Sheets or Excel.
Brand Count Share
Your brand 1500 =B2/$B$6
Competitor A 2700 =B3/$B$6
Competitor B 2100 =B4/$B$6
Competitor C 1200 =B5/$B$6
Total =SUM(B2:B5) =SUM(C2:C5)
Format column C as a percentage. You'll see 20%, 36%, 28%, 16%.
The check: C6 must say 100%. If not, you missed a brand.
Tip: keep the raw counts. A percentage with no counts behind it can't be checked later.
Paid search: impression share
Google Ads does the division for you.
Impression share = impressions ÷ eligible impressions.
4,200 impressions. Eligible for 12,000. That's 35%.
Two catches:
- "Eligible" is Google's estimate.
- It's not the market. Two advertisers can both have 70%.
To see competitors, open Auction insights.
Share of search
Share of search = searches for your brand ÷ searches for all brands × 100
Les Binet made this one popular in 2020.
How: put your brand and competitors into Google Trends. Export. Average each brand's index.
Example: you average 36. Competitors average 54, 18 and 12. Sum is 120.
36 ÷ 120 = 30%.
Heads up: Trends shows an index, not real counts. Use a 6 to 12 month rolling average to smooth it.
Measure What Matters: SEO Share of Voice
In SEO, share of voice is a share of clicks. Not mentions.
Ahrefs defines it as your clicks from tracked keywords ÷ all clicks for those keywords.
The spreadsheet version
- List your keywords, searches and position.
- Multiply searches by a click rate for that position.
- Add it up. Divide.
| Keyword | Searches × CTR | Clicks |
|---|---|---|
| A, position 2 | 2,000 × 15% | 300 |
| B, position 5 | 1,000 × 5% | 50 |
| C, page two | 500 × 0% | 0 |
| Total | 3,500 | 350 |
(The CTRs are examples. Build yours from your own Search Console data.)
Now the trick. There are two totals you can divide by:
- All clicks on those results: 350 ÷ 2,100 = 16.7%
- All searches: 350 ÷ 3,500 = 10%
Same site. Same rankings. Two answers.
Always say which one you used.
Local search: Share of Local Voice
A Local Falcon metric. How often you rank in the top three on a map grid.
A 7 by 7 grid has 49 points. Top three at 22 of them? 22 ÷ 49 = 44.9%.
Share of voice in AI answers
AI share of voice = your mentions ÷ all brand mentions in the same answers × 100
Real example. We asked five AI engines for the "best SEO tool":
31 mentions in total.
| Brand | Named by | Share of voice |
|---|---|---|
| Ahrefs | 5 of 5 | 16.1% |
| Semrush | 5 of 5 | 16.1% |
| Google Search Console | 4 | 12.9% |
| Screaming Frog | 3 | 9.7% |
| Surfer | 3 | 9.7% |
| Yoast SEO | 2 | 6.5% |
| SE Ranking | 2 | 6.5% |
| Seven others | 1 each | 3.2% each |
Three things this teaches you.
1. Mention rate is not share of voice.
Every engine named Ahrefs. That's a 100% mention rate. But it's only 5 of 31 mentions.
People mix these up all the time.
2. Every engine gives you a different share.
Why? Perplexity named 2 brands. Copilot named 13.
3. Don't average the engines.
The average of those five is 23.4%. The real pooled share is 16.1%.
Copilot supplies 13 of the 31 mentions. So it drags the pooled number down.
Show each engine on its own row.
One scan of one question, by the way. AI answers change every run. More on that in share of voice measurement.
Don't want to do this by hand? Our $49 report runs up to 50 prompts on five engines, daily for 7 days.
Does AI name you?
See if AI mentions your brand. Then get the pages to fix.
You Have Your Number. Now What?
One number tells you nothing.
Compare it:
- With last period. Same list.
- With each competitor.
- With your market share. (Ads only. That's ESOV.)
Then look behind the number:
| Channel | Look at | It tells you |
|---|---|---|
| Paid search | Lost IS (budget) vs (rank) | Budget problem or quality problem |
| SEO | Big keywords where you're not on page one | Where the clicks are |
| AI answers | Prompts that name rivals, not you | Which pages to fix |
| Social | Weeks a rival spiked | What they launched |
And don't panic over small moves. With 40 mentions in total, one mention is 2.5 points.
Where the number misleads
- Volume, not quality. A complaint counts the same as praise.
- Presence, not results. Nielsen says this too.
- Your list moves it. 20% to 15%, remember?
- Most inputs are estimates. Use it for direction.
Excess Share of Voice (ESOV) and monitoring
ESOV = share of voice − share of market
Positive ESOV means you shout louder than your size.
How to calculate ESOV
- Category ad spend: $2,000,000. Yours: $300,000. SOV = 15%.
- Category sales: $40,000,000. Yours: $4,000,000. Share of market = 10%.
- ESOV = 15 − 10 = +5 points.
What are 5 points worth?
- Nielsen, 2009. 123 brands, 30 categories. 10 points of ESOV went with 0.5 points of market share growth a year.
- Binet and Field. 0.6 points for consumer brands, 0.7 for B2B. The B2B report says the B2B number rests on under 50 cases. It calls the findings tentative.
So +5 points goes with about 0.25 points of share a year.
That's an illustration. Not a forecast. Deep dive: share of market vs share of voice.
The spend for a target ESOV
Want +1 point of share in a year? At Nielsen's average you need 20 points of ESOV. So 30% SOV.
Here's the trap. Your spend is in the total.
Target spend = target SOV × competitor spend ÷ (1 − target SOV)
0.30 × $1,700,000 ÷ 0.70 = $728,571
Just taking 30% of today's $2,000,000 gives $600,000. Which only gets you 26.1%.
These studies measured ad spend. Not social mentions, not organic clicks, not AI mentions. The 0.5 rule doesn't carry over.
Monitoring
Keep a log. One row per measurement: date, channel, brands, your count, total, share.
My cadence:
- Weekly: paid search impression share.
- Weekly or monthly: SEO and AI, on a frozen list.
- Monthly: share of search, as a rolling average.
- Quarterly: ESOV.
FAQs About Share of Voice
What is a good share of voice percentage?
There isn't one. An equal split is 100 ÷ the number of brands. Four brands: 25% each. Compare with last period instead.
What does 100% share of voice mean?
Your list is too small. Not a win.
How to calculate excess share of voice?
Share of voice minus share of market. Same category, same period. Worked example.
Is there a share of voice calculator?
It's one division. Use the sheet.
