AI share of voice
AI share of voice is the portion of brand mentions in AI-generated answers that go to your brand, compared with the competitors named in the same answers, across a defined set of prompts.
Example
Suppose you track 50 buyer prompts about project management software in one AI engine. Across the answers, your brand is mentioned 30 times and three competitors are mentioned 70 times between them. Your share of voice for that prompt set is 30 out of 100 mentions, or 30%.
How it is measured
Start with prompts that reflect the questions your buyers actually ask, then run them on each AI engine you care about. Count the mentions of your brand and of each tracked competitor, and divide your mentions by the total. The result depends heavily on which prompts and which competitors you include, so keep both stable if you want to compare periods.
AI answers can change from one run to the next, so a single run can mislead. Repeated readings over several days give a steadier picture, ideally reported as a range rather than one number. It also helps to measure each engine and each market separately: a blended figure can hide that you lead in one engine and are absent from another.
How Stellarcast handles it
Stellarcast calculates share of voice as mention share: your brand's mentions divided by the mentions of your brand plus the competitors you track. It is computed per engine and per market over a trailing window, from prompts written natively for each market, and shown with its P25-P75 range, which shows how much the figure could still move. Readings are stored date-stamped and append-only, so you can see what the number was on any past date.
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