What It Is, How to Measure It, and What It Actually Tells You

Sigh. Yet another metric marketers have to be raked over the coals for.

Jokes aside, AI share of voice can be useful. It tells you how visible your brand is in AI responses compared with your competitors.

But the number is only as meaningful as the way it’s calculated.

So in this guide, I’ll show you exactly what AI share of voice is, how it’s calculated, how to measure it in Brand Radar, and how not to read more into the number than it can tell you.

AI share of voice (AI SOV) is the share of AI visibility your brand captures compared with the competitors you track, across the prompts you care about.

A common way to calculate it is:

AI SOV = responses that mention your brand ÷ responses that mention any tracked brand × 100

Let’s say you track three prompts about email marketing software on ChatGPT, and compare your brand with two competitors. Here’s which brands each response mentions:

Every brand appears in two of the three responses, so each has 2 ÷ 3 = 67%.

But that treats every prompt equally, and “best email marketing software” is asked far more often than the ecommerce automation question. Appearing in that first answer puts you in front of many more people.

So in Brand Radar, we weight each prompt by AI-adjusted volume: the monthly Google search volume of the keyword behind the prompt, multiplied by a platform ratio. The ratio reflects how much traffic each AI platform sends to websites compared with Google organic search, based on Ahrefs’ traffic data.

For ChatGPT, it’s currently 0.115, so a 20,000-search keyword becomes 2,300 on ChatGPT.

When a response mentions your brand (or cites your website), that prompt’s AI-adjusted volume counts toward your estimated impressions. Your AI share of voice is your impressions divided by the impressions of all responses that mention any tracked brand (here, 2,300 + 920 + 115 = 3,335):

Same responses, same brands, but your share drops to 31% because your mentions come from the prompts people ask least. Impressions are a modeled estimate of exposure, not a count of people who saw an answer.

Each platform gets its own ratio, because people use them very differently: currently 0.115 for ChatGPT, 0.011 for Gemini, and 0.01 for Perplexity. So the same 20,000-search prompt carries 2,300 impressions on ChatGPT but only 220 on Gemini.

We calculate AI SOV per platform, and when you combine platforms, the overall score is a weighted average where platforms with more impressions count for more.

For example, let’s say the same prompts give you 28% AI SOV on ChatGPT and 11% on Gemini. Because ChatGPT carries roughly ten times the impressions, your combined score lands at about 26.5%, which hides the Gemini weakness almost completely.

So check each platform on its own before looking at the combined number.

Every number above depends on choices: which prompts, platforms, and competitors you track, where, and when.

Change any of them and the percentage changes, which is also why two tools can report different AI SOV for the same brand without either being wrong.

Only the second tells you what the 24% actually refers to.