Share of voice

Share of voice shows what proportion of the total visibility in your market goes to your business, compared with your competitors. The term originally comes from advertising, where it described a brand's share of the total advertising space. In online marketing you use it to measure how often and how prominently you appear for the searches and questions that matter in your sector.

The big advantage of share of voice is that it makes your position relative. Rising rankings are good news, but if your competitors are growing even faster, you are actually losing ground. Share of voice makes that visible.

How do you calculate share of voice?

There is no universal formula. The calculation depends on what you want to measure and what data you have. Common approaches are:

• In search engines: you put together a list of relevant keywords and calculate what share of the expected clicks goes to you, based on your ranking and the search volume per keyword.
• In AI answers: you put a fixed set of prompts to assistants such as ChatGPT, Gemini and Perplexity and count how often your business is named or cited as a source, compared with competitors.
• In advertising: the share of impressions your ads receive compared with the total possible.

What matters is that you use the same method and the same set of keywords or prompts every time. Only then can you compare changes fairly.

An example

A solar panel installer in Bristol tracks thirty searches, from "solar panel installation Bath" to "home battery grant". He discovers that he scores well on local searches, but is almost absent from informational questions about batteries, where two competitors have the largest share. In AI answers about home batteries, it is also mainly those competitors that are named. That gives a clear priority: develop content around a topic where his share of voice is low.

Without that comparison, he might have thought everything was going well, because his rankings for local keywords stayed stable. So share of voice shows not only where you stand, but also where you are leaving opportunities on the table.

Share of voice in AI search

In AI search environments, share of voice is arguably even more important than in traditional search results. An AI answer often names only a handful of businesses or sources. If you are not among them, you are invisible for that question. Because answers vary by moment and by wording, a single test is not representative. It is therefore best to measure your AI visibility across a set of prompts and over several measurements. That way you see trends rather than chance.

What to watch out for

• Choose competitors that genuinely serve the same customers, not just the biggest players.
• Avoid a list made up only of branded searches, because you will naturally always score highly there.
• Don't just look at numbers, but also at how you are mentioned: positively, neutrally or with a caveat.

Want to map your share of voice against your direct competitors, in both Google and AI answers? With competitor insights you see where you are ahead and where you are losing ground.