Market share data usually arrives late, costs money and is reported at a level too broad to act on. Branded search data, on the other hand, is free, updated constantly and available for almost every brand in almost every market. That is the idea behind share of search: if more people search for your brand than for your competitors, you are probably winning more of the category's attention, and often more of its sales.
The metric was popularised by effectiveness researcher Les Binet, who presented "Share of Search as a Predictive Measure" at the IPA's EffWorks Global 2020 event, exploring whether search volume can predict market share. Since then, brand and media teams have used it as a fast, low-cost proxy for brand health.
This guide explains how to calculate share of search, which data sources to use, how to read it alongside other metrics, and where it breaks down.
Key Takeaways
- Share of search = your brand's search volume ÷ total search volume for all brands in your category.
- It reflects brand demand and mental availability, and can move before sales data does.
- Define the competitor set carefully and keep it stable; changing it changes the metric.
- Use Google Trends for relative trends and keyword tools for estimated volumes; do not mix sources within one series.
- Treat it as a directional indicator alongside sales and share of voice, not a replacement for them.
What share of search measures
Share of search is your brand's portion of all branded searches in a category. If people searching for running shoes type five brand names, the share of search for each brand is its slice of the combined volume for those five names.
Why does that relate to market share? People search for brands they already know and are considering. Rising branded search usually reflects advertising, PR, word of mouth or product buzz that has put your brand into more buyers' heads. That is the same mental availability that tends to drive purchase. For more on building that demand, see our guide to brand awareness and the related concept of category entry points.
| Metric | What it measures | Data source | Speed |
|---|---|---|---|
| Share of search | Brand demand vs competitors | Search volume (Google Trends, keyword tools) | Fast, near real time |
| Share of voice | Your visibility or ad presence vs competitors | Ad spend, rankings, impressions, mentions | Fast |
| Market share | Your portion of category sales | Sales, panel or industry data | Slow, often quarterly or annual |
| Brand tracking survey | Awareness, consideration, preference | Surveys | Slow, costly |
How to calculate share of search
The formula is simple:
Share of search (%) = (searches for your brand ÷ searches for all brands in the set) × 100Semrush's share of search explainer gives a worked example: a brand with 120,000 searches in a set where competitors have 90,000, 50,000 and 75,000 has roughly a 36% share. The hard part is not the maths but the inputs.
- Define the category. Be specific: "UK meal-kit delivery", not "food".
- Choose the competitor set. Include every brand a buyer would realistically consider. Typically five to ten names.
- Pick the search terms. Use the core brand name plus common misspellings. Exclude terms that mean something else (a brand called "Apple" or "Mint" needs care).
- Choose one data source and stick with it for the whole series.
- Set the geography and time grain. Country-level, monthly data is a good starting point.
- Calculate and chart the trend for each brand over at least a year to see seasonality.
- Compare against sales or market share where you have it, to see whether the relationship holds in your category.
Choosing a data source
| Source | Strengths | Limitations |
|---|---|---|
| Google Trends | Free, long history, compare several terms on one chart, topic entities handle ambiguity | Relative index not absolute volume; sampled data; limited number of terms per comparison |
| Keyword research tools | Estimated monthly volumes, many brands at once | Estimates vary between tools; may lag |
| Google Ads Keyword Planner | Data direct from Google | Ranges for low-spend accounts; grouped close variants |
| Your own Search Console | Accurate impressions for your brand queries | Only your site, no competitor data |
Google Trends is the most common choice, but it is important to understand what its numbers are. Google explains that Trends data is normalised and scaled:
“The resulting numbers are then scaled on a range of 0 to 100 based on a topic’s proportion to all searches on all topics.”
— Google Trends Help, FAQ about Google Trends data
Because each Trends chart is rescaled, always pull all competitors in the same comparison. If you have more brands than one comparison allows, include your own brand in every batch as an anchor and rescale the batches against it. Trends is also based on a sample of searches, so very small brands can show noisy or zero values.
How to use share of search in practice
- Early warning. A sustained drop in your share while competitors rise is worth investigating before it shows up in sales.
- Campaign evaluation. Look for step changes in share after big brand campaigns, PR moments or product launches.
- Budget conversations. Combine with marketing mix modeling to show how brand investment builds demand over time.
- Competitive tracking. Add it to your competitive benchmarking dashboard next to share of voice and rankings.
- SEO prioritisation. Branded demand affects how much organic and paid traffic you can win; see branded vs non-branded keywords.
Share of search in an AI-search world
In 2026 more research happens inside AI assistants and AI Overviews, which do not report query volumes to marketers. Branded Google searches still capture a large part of demand, but treat share of search as one lens. Monitoring how often AI tools mention your brand, covered in our guide to AI brand visibility, gives a complementary view.
Common mistakes with share of search
- Ambiguous brand names. A brand that shares a name with a common word will look artificially large. Use Trends topics or add qualifiers.
- Navigational noise. Searches like "[brand] login" come from existing customers. That is still brand demand, but a spike from an outage is not growth.
- Changing the competitor set. Adding or removing a brand changes everyone's share. Keep the set fixed, or restate history when you change it.
- Mixing data sources. Trends indices and tool volume estimates cannot be combined in one series.
- Assuming causation. A correlation between share of search and sales in one category is not proof it holds in yours. Test it against your own data.
- Reading weekly noise. Use monthly or rolling averages; weekly data swings with news and seasonality.
Related Guides
- Microsoft Clarity: Free Session Recordings and Insights
- GA4 Ecommerce Tracking: Setup and Key Reports
- How to Track Form Submissions in GA4 and GTM
Frequently Asked Questions
What is a good share of search?
There is no universal benchmark. Compare your share to your actual market share: if share of search is higher, you may be building future growth; if lower, demand may be weakening.
Is share of search the same as share of voice?
No. Share of voice measures how visible you are (ads, rankings, mentions). Share of search measures how much people actively look for you, which reflects demand rather than exposure.
Can small businesses use share of search?
Yes, but low volumes make Google Trends data noisy. Use a keyword tool's monthly estimates, a local geography and a longer time window.
How often should I measure share of search?
Monthly is a sensible default. Track it continuously, but make decisions on rolling averages rather than individual weeks.
Does share of search predict market share?
Research presented by Les Binet suggested it can be a useful predictor in many categories, but you should validate the relationship against your own sales data before relying on it.
Conclusion
Share of search is one of the cheapest, fastest brand health metrics available. Calculate it consistently, interpret it alongside sales and share of voice, and use it to spot shifts in demand early. If you want help building brand and organic demand that shows up in these numbers, explore our SEO services or get a quote.
