Share of search is the share of all branded searches in your category that go to your brand. To work out how to calculate share of search, take the searches for your brand, divide them by the searches for every brand in your competitor set, and multiply by 100. You can do it free in Google Trends in under an hour, and the number often moves before your market share does.
This guide gives you the formula, a seven step method, a worked example, a monthly template and the traps that make the number lie.
The short version
- The formula is simple. Searches for your brand divided by searches for all brands in your competitor set, times 100.
- Google Trends is enough. Put every brand in one comparison, export the CSV and average the values. It is free and goes back to 2004.
- Smooth it. The IPA think tank recommends a 6 to 12 month rolling average because short term data is noisy.
- Compare it with share of market. If your share of search is above your share of market, you may be set to grow. If it is below, watch out.
- It is a signal, not proof. The IPA stresses these are correlations, not causes. Bad press, double meanings and price all distort it.
What is share of search?
Binet defines share of search as the share of organic Google search queries for a brand, not share of paid search advertising. In the IPA's words, the metric "equates to total searches for a specific brand, divided by the total searches for all brands in that category" (IPA, October 2020). People search for brands already in mind, so searches are a cheap proxy for how often a brand comes to mind.
Binet tested it in cars, energy and mobile phone handsets and found share of search correlated with market share in all three. The 2021 IPA think tank, presented by James Hankins of Vizer Consulting, widened that to 30 case studies and reported that share of search "appears to represent 83% of a brand's Share of Market on average" (IPA, October 2021). The underlying deck gives the average correlation as 0.82 and calls share of search "a good proxy for aggregate Mental availability" (IPA think tank deck).
How far ahead share of search moved before market share, by category
Share of search vs share of voice vs share of market
The three metrics answer different questions. Share of voice tells you how loud you are. Share of search tells you how much people are thinking about you. Share of market tells you how much they are buying. The well known rule from Binet and Peter Field is that every 10 points of excess share of voice tends to deliver about 0.5 points of extra market share a year (IPA blog, 2023; Nielsen, 2025). Share of search sits in the middle: it moves faster than sales and costs nothing.
| Metric | What it measures | Where the data comes from | Best used for |
|---|---|---|---|
| Share of search | Your brand searches as a share of all brand searches in the category | Google Trends or Keyword Planner, free | An early read on demand and mental availability |
| Share of voice | Your ad spend or impressions as a share of the category | Media spend data, monitoring tools | Deciding how hard to push investment |
| Share of market | Your sales as a share of category sales | Sales, panel or industry data | The outcome you are trying to move |
Advertain guidance, based on the IPA and Kantar definitions cited below.
Kantar puts the diagnostic neatly: "Higher Share of Search than Share of Market for your brand and you could be primed for growth… Lower Share of Search than Share of Market for your brand suggests a risky future trajectory" (Kantar). If you already track awareness, read our guide on how to measure brand awareness first; share of search slots into that toolkit as the cheapest leading indicator.
How to calculate share of search in Google Trends: 7 steps
1. Define your category and competitor set
List the brands that take most of the category's branded searches, not just your favourite rivals. Binet's car analysis used 23 brands; for most categories five to ten will do. Keep the list fixed, because adding a brand later changes everyone's share.
2. Build a clean search term for every brand
Check each brand name in Google Trends on its own first. Google says you "won't get results for misspellings, spelling variations, synonyms, plural, or singular versions of your terms" (Google Trends Help), so combine variants with a plus sign, for example "brightbean + bright bean". You can also put a minus sign in front of a word to exclude it. Where a brand name is a common word, use the Topic version if one exists, or add a qualifier. Kantar's example is "dodge", which also catches the verb, dodgeball and the Los Angeles Dodgers (Kantar, 2025).
3. Pull the data from Google Trends
Put every brand into one comparison so they share the same scale. The current Explore view lets you "compare up to 8 groups of terms at once and up to 50 terms in each group", while Classic explore allows 5 groups (Google Trends Help). Set the country, choose at least the past 12 months (five years is better for trends) and keep the category filter identical for every pull. Then export the CSV, which Google supports directly (Google Trends Help).
4. Calculate share of search
Google Trends does not give raw search counts. Each value is normalised: "Each data point is divided by the total searches of the geography and time range it represents" and then scaled from 0 to 100 (Google Trends FAQ). That is fine for a ratio. For each period, divide each brand's value by the total of all brands' values and multiply by 100. The IPA formula is "Searches for brand X / Searches for all the brands in the competitor set" (IPA think tank deck).
5. Smooth it with a rolling average
Weekly data jumps around. The IPA think tank recommends "a 6 to 12 month rolled average", noting much of its evidence uses a 12 month rolling average and that "significant variation occurs below this" (IPA think tank deck). Small brands need extra care: Trends works in whole numbers, so a move from 1 to 2 looks like a 100% jump. The think tank suggests pulling the data on several days and averaging the results.
6. Compare it with share of market and share of voice
Line your share of search up against your latest share of market. The difference is what Binet calls extra share of search, which the IPA describes as "a particularly solid indicator of market share movements" (IPA, 2020). If you outspend the category but share of search is flat, the creative may not be building memory.
7. Report it monthly and act on it
Add one row a month to the template below, annotate campaigns and press stories, and write a one line conclusion. Pair it with our social media ROI guide to connect it to commercial results.
A worked example
Here is the calculation for four fictional coffee pod brands. Over 12 months their average Google Trends values were 42, 27, 13 and 8, a category total of 90. Harrow Roast's share of search is 42 divided by 90, which is 46.7%. Brightbean's is 27 divided by 90, which is 30.0%.
Worked example: share of search in a fictional UK coffee pod category
| Brand | Average Trends index | Share of search | Share of market | Gap (points) |
|---|---|---|---|---|
| Harrow Roast | 42 | 46.7% | 52% | 5.3 below |
| Brightbean | 27 | 30.0% | 24% | 6.0 above |
| Kettlewell | 13 | 14.4% | 15% | 0.6 below |
| Northfield | 8 | 8.9% | 9% | 0.1 below |
| Category total | 90 | 100% | 100% |
Illustrative worked example with fictional brands and figures. Share of search = brand index divided by category total. A positive gap suggests a brand may be set to grow share.
Now compare. Brightbean has 30.0% of searches but only 24% of sales, a gap of 6 points. That brand may be about to gain share, or it may have a distribution or price problem stopping searchers from buying. Harrow Roast sells more than its search share suggests, which can mean it is living off past fame. As Kantar's Adele Jolliffe and Si Atherley warn, if share of search grows faster than share of market, "you might have a conversion problem" (Marketing Society). Neither reading is automatic; the number tells you where to look.
"There's very little correlation between how much people talk about brands on social media and how those brands do in the real world." Les Binet, speaking to Contagious, 2020
Common mistakes that make share of search lie
- Counting bad news as growth. Not all search is positive. Kantar points to Tesla's share of search jumping in June 2024 as Cybertruck recalls drew attention (Kantar).
- Using it in price led categories without caution. Binet found the lead in energy was real but short, and that "price plays such a big role that forecasting market share is not practical" (Binet deck).
- Changing the competitor set. Adding or removing a brand changes every share. Keep the set fixed and note any change.
- Mixing data sources. Google says Trends and Google Ads are different data sources and asks people not to cite them together (Google Trends Help). Keyword Planner gives average monthly searches for exact matches, rounded (Google Ads Help), so pick one source and stick with it.
- Ignoring AI search. Google says Trends excludes searches made by Google products, including internal searches made by AI Mode and AI Overviews (Google Trends FAQ). Google brand searches are a strong signal but not the whole picture; see also our guide to YouTube SEO.
Share of search template and checklist
| Column | What to put in it |
|---|---|
| Month | The month the data covers |
| Brand index (one column per brand) | Monthly average of the Google Trends value for each brand term |
| Category total | Sum of all brand indexes that month |
| Share of search (one column per brand) | Brand index divided by category total, as a percentage |
| Rolling 12 month share | Average of the last 12 monthly shares for your brand |
| Share of market | Latest sales share, if you have it |
| Gap | Share of search minus share of market, in points |
| Notes | Campaigns, launches, price changes, press stories |
Advertain template. Build it in any spreadsheet and paste the Trends CSV into a raw data tab each month.
Before you share the number, check:
- The competitor set covers the brands that genuinely take most of the category's searches, and it stays the same every month.
- Every brand term has been checked in Google Trends for double meanings, sub brands and common misspellings.
- All brands sit in the same comparison, same country, same time range and same category filter.
- You are using at least 12 months of weekly or monthly data and a 6 to 12 month rolling average.
- The CSV export and the date you pulled it are saved, because Trends is a sample and values shift slightly between pulls.
- Share of search sits next to share of market and share of voice, not on its own.
- News spikes and crises are annotated so nobody mistakes bad press for brand growth.
- One owner reports it monthly with a one line "so what" for the marketing team.
How to increase share of search
You do not move share of search by gaming search. You move it by putting distinctive, memorable work in front of more category buyers, consistently. Binet's work suggested around 40% of an ad's effect on search showed up in the first month and around 60% over the following two years (Contagious; IPA), and the IPA deck reports an average 20% fall in share of search after two dark quarters (IPA think tank deck). Large brands now use the metric seriously: WARC reports that adidas tracks brand health through organic search data across 38 countries and has cut tracking costs by 60% (WARC, 2025).
For the brands we work with, the lever is usually video people choose to watch. Our paid vs organic social media report covers where to put that budget, and you can see examples in our work, such as the Formula E content that drew 7M+ views across YouTube, Instagram and TikTok.
Frequently asked questions
What is share of search?
Share of search is the percentage of all branded searches in a category that are for your brand. Les Binet popularised it at the IPA in 2020.
How is share of search calculated?
Divide the searches for your brand by the searches for all brands in your competitor set and multiply by 100. With Google Trends, use the index values from a single comparison and smooth the result with a 6 to 12 month rolling average.
What is the difference between share of search and share of voice?
Share of voice measures your share of category advertising. Share of search measures your share of category brand searches.
Can you use Google Trends for share of search?
Yes. Google Trends is the standard free source. Its data is a sample that is normalised from 0 to 100 and low volume terms show as 0, so it works best for brands with meaningful search volume and over longer time ranges.
How do you increase share of search?
Grow mental availability: reach more category buyers with distinctive, memorable creative, keep investing rather than going dark, and make the brand easy to find.
Want help building a brand people actually search for? Talk to us.
