Keyword Difficulty Explained: How to Pick Blog Topics You Can Rank For

Most business blogs fail before the first word is written, at the choice of topic. Either nobody searches for it, or everybody does and the first page belongs to companies a hundred times your size. Keyword difficulty is the number that helps you avoid the second mistake.

This guide explains what the score means, where it misleads, and how to combine it with search volume into one simple estimate of what a topic can bring you.

What keyword difficulty measures

Keyword difficulty (often shortened to KD) is a score from 0 to 100 that estimates how hard it is to rank on Google’s first page for a search term. SEO tools calculate it mainly from the pages that rank today: how many other sites link to them and how strong those sites are.

The logic is simple. If the first page is full of pages with hundreds of links from respected sites, a new post from a small site has little chance. If the top results are forum threads and thin pages from small sites, a good post can get in.

Two things to keep in mind:

• It is an estimate. Google does not publish a difficulty score. Every tool has its own formula, so a 35 in one tool can be a 50 in another. Compare topics within the same tool.
• It is relative to you. A score of 40 is hard for a new site and easy for a well-known brand. As your site earns links and rankings, more topics come within reach.

Why search volume alone misleads

Search volume is the average number of times a term is searched per month. It is tempting to sort a topic list by volume and start at the top. That is how blogs end up with ten posts aimed at searches they will never win.

Consider two topics for a window company:

• “windows”: hundreds of thousands of searches, dominated by Microsoft and national retailers. Chance for a local installer: zero.
• “triple pane vs double pane windows”: a few thousand searches, results from mid-sized blogs. Chance with a thorough post: real.

There is a second reason to prefer the specific topic. The person searching “windows” could want anything. The person comparing triple and double pane is planning a purchase. Specific searches are easier to win and worth more when you do.

Volume and difficulty together: potential

To compare topics fairly you need one number that includes both demand and your chance. A simple version:

Potential = monthly searches x click share x chance to rank

• Monthly searches: the volume of the main term.
• Click share: the part of searchers who click a top result. A cautious assumption is about 10% for a page in the top three.
• Chance to rank: the inverse of difficulty. A practical shortcut is 1 minus difficulty divided by 100.

Here is what that looks like for four topics:

The numbers are example values for illustration. Look at the last row. It has by far the most searches, but at difficulty 78 a small site is unlikely to get near the top, so that number is mostly theoretical. The first and third rows are the ones to write first: good demand and a realistic fight.

The formula is rough on purpose. Its job is not to predict traffic to the visitor. Its job is to put your topic list in a sensible order.

Three checks the score cannot do for you

Does the search match what you offer?

A topic can have perfect numbers and still be useless if it attracts the wrong people. “How to repair a window yourself” brings do-it-yourselfers, not customers for a replacement company. Ask what the searcher wants to do next and whether you are the right next step.

What does the first page actually look like?

Search the term yourself. If the results are guides and comparisons, a blog post fits. If they are shop category pages or maps of local businesses, Google has decided that searchers want something else, and a blog post will struggle no matter how low the difficulty is.

Is it worth something?

The price advertisers pay per click (CPC) is a useful hint. A term with a high CPC means businesses earn money from those visitors. A topic with modest volume but a high click price can be worth more than a popular one with none.

How to build your topic list in five steps

1. Collect the questions customers ask before they buy, on the phone, in email and in reviews.
2. Turn each into a search term and look up monthly searches and difficulty in a keyword tool. Google’s Keyword Planner gives rough volumes for free.
3. Drop topics without demand and topics far above your level.
4. Estimate the potential with the formula above and sort the list.
5. Write from the top, one post per topic, and link related posts to each other.

Then keep going at a steady pace. A sorted list of thirty topics is more than half a year of weekly posts. How fast to work through it is covered in how often you should blog, and what each post needs on the page is in the Wix blog SEO checklist.

Frequently asked questions