What is AI share of voice?
AI share of voice is your brand's share of all the brand mentions in AI answers to a set of questions. If 100 answers mention brands 250 times in total and 25 of those mentions are yours, your share of voice is 10%. It tells you how crowded the answers are and how much of the conversation you hold, which a mention rate on its own cannot.
What is the formula for calculating AI Share of Voice?
AI share of voice = mentions of your brand divided by mentions of every brand in the set, across the same answers. Count each brand at most once per answer, so a single answer that repeats a name five times does not outweigh four answers that name it once.
The formula is simple. The part that decides the number is the denominator: which brands count as "every brand". There are three honest choices, and a share of voice figure should always say which one it uses:
- Among tracked brands: your mentions as a share of mentions of you and the competitors you chose to track.
- Among every vendor named: your mentions as a share of mentions of every brand the answers named, tracked or not.
- Among the top 10 vendors named: your mentions as a share of mentions of the ten brands named most often, plus yours if you rank lower.
How does the brand set change the number?
The same answers can give very different shares depending on the set. In the public Tesla example (4 Oct 2026), 53 answers to 25 buyer questions named Tesla. Against the four rivals named most often (Rivian and SunPower in 13 answers each, Ford in 10, Enphase Energy in 9), that is 53 of 98 mentions, a 54% share of voice.
Add General Motors, named in 7 answers, and nothing about Tesla changes, yet the share falls to 53 of 105, or 50%. Widen the set to every brand the answers named and it falls further. None of these figures is wrong. A share of voice quoted without its set is the one that misleads.
| Brand | Answers naming it | Share of the five | Share of the six |
|---|---|---|---|
| Tesla | 53 | 54% | 50% |
| Rivian | 13 | 13% | 12% |
| SunPower | 13 | 13% | 12% |
| Ford | 10 | 10% | 10% |
| Enphase Energy | 9 | 9% | 9% |
| General Motors | 7 | not in set | 7% |
How is share of voice different from mention rate?
Mention rate asks how often you appear at all; share of voice asks how much of the answer space you hold when brands appear. The two can move in opposite directions.
If a new competitor starts appearing in every answer, your mention rate can stay flat while your share of voice drops. If engines start naming fewer brands per answer, your share can rise while your mention rate falls. Read them together: mention rate for presence, share of voice for crowding, and citation share for the sources behind both.
Can AI Share of Voice be segmented by topic, market, or customer intent?
Yes, and it usually should be, because a brand can lead one topic and be absent from the next. A single share across every question averages away the topic where you are losing.
In the Tesla example, the topic split is stark: Google AI Overviews named Tesla in 4 of 5 solar panel installation answers while Claude named it in none of the same 5. Segmenting by topic and by engine shows where the share is won and lost; prompt coverage shows the same split question by question.
Where do you see share of voice in Proofsource?
Proofsource shows share of voice beside mention rate, labelled with the set it is a share of: among tracked brands, among every vendor named, or among the top 10 vendors named, with the numerator and the denominator in one line. The AI Visibility feature page shows the screen.
Common questions about AI share of voice
What is a good AI share of voice?
There is no universal figure, because it depends on how many brands your category's answers name and which set the share is taken over. Compare yourself with the brand named most often for the same questions on the same engines, using the same set, and watch the trend after each change you make.
Do these tools include competitor and share-of-voice tracking?
Most AI visibility tools report some form of share of voice next to the competitors named in the same answers. Check what each one divides by: a share among five tracked rivals and a share among every brand named are different numbers for the same answers.
How many prompts and competitors are needed for a reliable comparison?
Enough answers that the gap between two brands is larger than the uncertainty in each share, and enough competitors that the set reflects who the answers actually name. Start from the brands the engines name most often for your buyer questions, not only the ones you consider rivals, and let repeated runs build the sample.
How should I compare my score with competitors fairly?
Use the same questions, the same engines, the same period and the same brand set for every brand, count each brand once per answer, and keep the interval in view. Two shares that differ by less than their uncertainty are not yet a ranking.
Related terms
- AI visibility
AI visibility is how often AI assistants such as ChatGPT, Perplexity, Claude and Google AI Overviews name your brand when people ask about your category.
- Citation share
Citation share is the share of all the citations in AI answers that point at a given website.
- Prompt coverage
Prompt coverage is how much of your set of tracked buyer questions AI engines answer with your brand named, broken down by question, topic and engine.
- Query fan-out
Query fan-out is when an AI engine splits one question into several related searches and builds its answer from all the results.
Worked example: Tesla, public AI answers, 4 Oct 2026: Proofsource's first scan of Tesla, 25 buyer questions and 5 brand questions, one answer per question on each of four engines. A small sample from one brand, shown as an example, not a benchmark.
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