What the estimator is for
The Organic Traffic Growth Estimator takes what you already know about a keyword, your current position in Google, and how that position might change, and turns it into an approximate number of extra visitors you could expect each month. It exists because most of the work involved in search engine optimisation (SEO, the practice of improving a page so it ranks higher in unpaid search results) takes weeks or months to show results, and business owners are being asked to commit that time before they can see whether it will pay off.
You can try the tool itself on the Organic Traffic Growth Estimator page. This guide explains what it is doing behind the scenes, so the number it gives you means something.
The problem it solves
Say you run a small joinery business in Leeds and your web developer suggests spending three months improving your site so it ranks for "bespoke kitchens Leeds". That is a reasonable-sounding suggestion, but it tells you nothing about whether the effort is worth it. Will moving from position 14 to position 4 bring you two extra enquiries a month or twenty? Without some way of sizing the reward, you are choosing between competing priorities blind.
Organic traffic, meaning visitors who arrive at your site through unpaid search results, is one of the few traffic sources that keeps working without ongoing spend once a page ranks well. That is exactly why it is worth estimating before you invest the time.
How the calculation works
The inputs it asks for
The estimator needs a handful of things from you, each of which you can usually find in a few minutes using Google Search Console (a free tool from Google that shows how your site performs in search results):
- The monthly search volume for the keyword, meaning roughly how many times people type that phrase into Google each month
- Your current ranking position for that keyword, if you have one
- The position you are aiming for
- A timeframe over which you expect to move between the two
If you have not used Search Console before, it takes about ten minutes to set up and will show you which keywords your pages already rank for and where, which is usually the fastest way to fill in the first two fields honestly.
The maths behind the estimate
Once it has those inputs, the tool applies a click-through rate (CTR, the percentage of people who see a listing in the search results and actually click it) for each ranking position. A listing at the very top of page one gets clicked far more often than one halfway down, and the gap between position three and position ten is usually much larger than people expect, because most searchers never scroll past the first few results. The estimator multiplies the monthly search volume by the CTR for your current position to estimate your current traffic, then does the same for your target position to estimate what you could get, and shows the difference as a monthly growth figure spread across your chosen timeframe.
None of this is measured from your actual site. It is a model built on typical click behaviour, so it should be read as a plausible range. Search engines change how results are displayed, competitors change their own pages, and two keywords with identical search volume can behave quite differently depending on who else is ranking for them.
A worked example
Take a keyword with a monthly search volume of 200 searches. If your page currently sits at position 9, it captures only a small slice of those searches, perhaps somewhere in single figures a month, because most people click one of the first few results and stop looking. If you improved the page enough to reach position 3, the same 200 searches would send considerably more traffic your way, because the CTR at position 3 is several times higher than at position 9.
Run that through the estimator over a six-month timeframe and it will show you a monthly growth curve, because rankings tend to move gradually as Google reassesses your page. That curve is the useful part: it gives you something to compare against the cost of the work, whether that is your own time or a freelancer's invoice, before you commit to it.
Using the estimator step by step
- Open Google Search Console and find a keyword your site already ranks for on page one or two
- Note its current average position and its monthly search volume, or use a keyword research tool if the page is not yet ranking at all
- Decide on a realistic target position, based on what the pages currently occupying that spot look like
- Enter both positions, the search volume, and a timeframe into the estimator
- Read the estimated traffic growth as a range to plan around.
If you are trying to decide which of several keywords to prioritise, run each one through the estimator separately and compare the outputs side by side. The Promotion Channel Prioritiser is useful for the wider question of whether SEO should be your main focus at all, alongside paid search, social media, or other channels.
Where the estimate can mislead you
The most common mistake is treating the output as a guarantee. The estimator cannot know how strong your competitors' backlink profiles are (backlinks are links from other websites pointing to yours, and they remain one of the strongest signals Google uses to decide rankings), so two sites aiming for the same position can face very different amounts of work to get there.
A second mistake is assuming growth will be linear. Search rankings tend to move in steps, often staying flat for weeks before a page update or a batch of new backlinks shifts things noticeably. A third is using national search volume for a business that only serves one city or region, which inflates the estimate well beyond what a local audience could realistically deliver. Finally, seasonal keywords, anything tied to a time of year such as "Christmas hampers" or "summer holiday cottages", will show search volume that is only accurate for part of the year, so check whether the figure you have entered reflects the season you are planning for.
What to do with the number
Once you have an estimate, use it to decide whether the work is worth doing. If the projected growth looks small next to the effort required, that is useful information too, because it points you towards a different keyword or a different channel altogether. Pages like the Website Promotion Playbook cover how organic search fits alongside other ways of getting a website found, if SEO turns out not to be the best place to put your time right now.