Guide
Share of Search: What It Is and How to Calculate It
Share of search is a brand's share of all the branded searches in its category. Add up the searches for every brand you compete with, then divide your brand's searches by that total. It's free to measure, updated monthly, and it tends to move before market share does.
Key takeaways
- Share of search is a brand's share of all the branded searches in its category.
- To calculate share of search, add up the searches for every competing brand and divide your brand's searches by that total.
- Share of search is free to measure and updates monthly.
- Marketers watch share of search because it tends to move before market share does.
- Share of search is different from share of voice, which measures a brand's share of advertising or media presence.
- AI share of voice measures how often a brand is mentioned in AI answers compared with competitors; it complements share of search rather than replacing it.
Share of search calculator
Enter each brand’s monthly searches. Add last year’s numbers to see who gained and who lost. Nothing you type leaves your browser.
| Brand | Searches now | A year ago (optional) | Share | Change |
|---|
The starting numbers are illustrative, not real brands.
Why do marketers use share of search?
Because it’s a free, monthly read on brand demand when market share data is slow, expensive or missing. Les Binet’s analysis for the IPA, presented at EffWorks in 2020, found that share of search correlates with market share and often moves ahead of it, which makes it a useful lead indicator of brand health.
It also reframes a familiar idea. Binet and Field found that brands whose share of voice runs above their share of market tend to grow. Share of search asks the same question from the demand side: are more people looking for you than your current share would predict?
How do you calculate share of search?
Divide one brand’s branded searches by the total for every brand in its competitive set, then multiply by 100. The work is in choosing the set and the search terms.
- Pick the competitive set. Choose the brands a buyer actually weighs against yours, usually four to eight. Leave out retailers and marketplaces unless you compete with them for the same purchase.
- Pick the search terms for each brand. Use the brand name and its common misspellings. When the name is also an everyday word, use the brand plus its product ("dove soap”, not “dove"). Use the same rules for every brand.
- Get monthly volumes. Google Trends compares up to five terms on a relative scale and is free. Google Keyword Planner, Ahrefs and Semrush give absolute monthly estimates. Use one source for every brand.
- Divide. Each brand’s searches ÷ the total for all brands in the set × 100.
- Smooth and compare. Use a 12-month average, or compare the same month year on year, so seasonal peaks don’t read as gains. The trend matters more than any single month.
How do you read the number?
Compare share of search with market share, and always look at the raw search volume next to it.
- Above market share: more people are looking for the brand than its sales share would suggest. Growth tends to follow.
- Below market share: the brand is living off past demand. Expect share to slip unless something changes.
- Rising share, falling searches: check both numbers. In Recon’s sample brief on Duolingo, US branded search fell 5.0% in a year, yet share of search rose to 92.1% because almost every rival fell faster. A rising share can hide a shrinking category.
Common mistakes
Most bad share-of-search numbers come from the inputs, not the maths.
- Ambiguous names. A brand that shares its name with a word, a place or a person picks up searches that have nothing to do with it. Add the product word to the term, the same way for every brand.
- Spikes that aren’t demand. A recall, a lawsuit or a viral moment sends searches up for a month. Not every search is a buyer, so note the event and judge the trend around it.
- An unfair set. Adding a giant from a neighboring category, or leaving out the fastest-growing challenger, changes the answer more than anything the brand did. Write down why each brand is in the set before you look at the numbers.
- Mixing sources. Trends, Keyword Planner and third-party tools estimate differently. Pick one source and use it for every brand, every month.
- Parent vs product brands. Decide whether you’re measuring the company or a product line, and keep to it.
Using share of search in an interview
Bring it to any brand, growth or CMO interview: it’s a number the team will recognize and few candidates bring. A line like “your share of search held while branded searches fell 5%, so the category is shrinking around you” opens a real conversation about strategy. Put the point in your own words and add your own read on why it’s happening; the number gets their attention, and your take is what they’ll remember. You don’t need paid tools for this: a free Google Trends comparison is enough to start. For the rest of your research, see how to research a company before an interview, and look up related terms in the marketing metrics glossary.
How do you increase share of search?
You grow share of search by making more people think of your brand when they need the category, which is mostly a long-term brand job. Binet’s IPA work found that sustained advertising drives most of the searches, with a short-term spike from each burst that fades quickly. In practice:
- Keep brand advertising running, not only in bursts, so the long-term effect builds.
- Give people a name to search: distinctive product names, campaigns and creators that send people to search for you.
- Earn coverage and conversation, since news, social and word of mouth all show up as branded searches.
- Watch competitors’ share too: a rival’s big launch can cut your share even when your own searches hold.
What is share of voice in AI search?
AI share of voice is how often your brand is mentioned or cited in AI answers (ChatGPT, Perplexity, Gemini, Google’s AI Overviews and others) compared with competitors, for a set of prompts in your category. It’s a newer metric than share of search and each tool counts it differently. Ahrefs’ Brand Radar, for example, weights mentions by how often each prompt is searched. Treat it as a read on visibility in AI tools, alongside share of search, not a replacement for it.
FAQ
Is share of search the same as share of voice?
No. Share of voice is a brand’s share of advertising or media in its category: what the brand puts out. Share of search is its share of the searches people make: the demand that comes back.
Can I measure share of search for free?
Yes. Google Trends compares up to five terms at once in its classic view and more on its newer Explore page (Google’s help page), which covers most competitive sets. For more brands, keep one brand in every comparison so you can join the results on the same scale.
How often should I check share of search?
Monthly is enough. Read it as a 12-month trend, not a monthly score.
Does share of search work for B2B brands?
It works when buyers search for brands by name. In small B2B categories the volumes can be too low to be stable, so treat changes of a point or two as noise.