AI search share of voice: definition, formula and pitfalls

Share of voice (SOV) in AI answers is a brand's mentions as a share of all tracked brands' mentions across a defined set of answers.

It's a relative measure. If you and two competitors are named 24, 31 and 22 times in 60 valid answers, your SOV is 24 ÷ (24 + 31 + 22) ≈ 31%.

#Formula

SOV(brand) = mentions(brand) ÷ Σ mentions(all tracked brands)
Mention rate(brand) = mentions(brand) ÷ valid answers

They answer different questions. SOV tells you how you split the conversation with named rivals. Mention rate tells you how often you appear at all. A category where nobody is mentioned much can give you a big SOV and a small mention rate.

#Define everything around it

An SOV figure without its frame is not meaningful. Always state:

• The prompt set — which questions, how many, which stage.
• The engines — and the model versions where known.
• Location and language.
• The time window and number of runs per prompt.
• The brand list — SOV changes when you add a competitor.
• What counted as valid — failed collections are not absences.

#How many answers do you need?

Small samples produce wide uncertainty. If you checked 20 answers and a brand appeared in 5, the plausible range for its true mention rate is roughly 11%–47% (a 95% Wilson interval). A brand at 7 of 20 overlaps almost entirely with it.

Practical rules:

• Don't call a difference real unless the intervals clearly separate.
• Prefer more repeated runs of a stable panel over more prompts you won't act on.
• Use our share-of-voice calculator to see the intervals for your numbers.

#Pitfalls

Counting mentions per answer instead of answers. If a single answer names a brand three times, it is still one answer mentioning that brand. Decide a unit and keep it.

Blending stages. A strong showing in problem-stage questions can hide a weak one in comparisons. Segment before you average.

Position weighting without disclosure. Some tools weight earlier mentions more. That's legitimate, but publish the weighting.

Mixing branded and non-branded prompts. A prompt that names you guarantees you're mentioned. Keep branded prompts out of SOV.

Forgetting citations. A brand may dominate mentions while a competitor dominates the sources. Report both. See AI citation tracking.

#Reporting template

Fill in your own numbers; keep the structure.

#Sources

• Wilson score interval: Wilson, E. B. (1927), "Probable inference, the law of succession, and statistical inference", Journal of the American Statistical Association.
• Aggarwal et al., GEO: Generative Engine Optimization.