How Many Keywords Do You Really Need For Content Research?

The short version: for one piece of content you need 3 to 5 keywords in a tight cluster, for a quarter's content plan you need 12 to 20 topics you can write, and for a full research pool you build out 150 to 400 keywords and then throw most of them away. The number people quote (500, 1,000, "as many as you can find") is a vanity metric that has nothing to do with what gets published or ranked.

Why the "more is better" advice took over

I've been doing content and SEO work since 2011, and somewhere along the way keyword research turned into a spreadsheet flex. I've sat in meetings where an agency proudly presented a client with 2,400 keywords in a Google Sheet, colour-coded by volume, with zero indication of which ones the client's three-person team could ever write about. It looked impressive. It was useless.

Tools push this behaviour because tools are built to generate long lists. Type one seed term into Ahrefs, SEMrush, or Ubersuggest and you'll get hundreds of variations back in seconds. The tool did its job. But a list of 800 keywords isn't a content strategy, it's a haystack, and someone still has to find the needle, which is the 15 or so topics that will move the needle for that specific business this quarter.

The number I use, by stage

I break keyword research into three tiers, because "how many keywords do I need" is really three different questions depending on what you're doing.

Tier 1: a single piece of content

For one blog post or landing page, you need one primary keyword and 3 to 5 supporting keywords that are semantically related, not random. If I'm writing about "email marketing for small business," the supporting keywords aren't "email marketing tips" and "email marketing software" bolted on for volume, they're the actual questions someone asks around that topic: how often to send emails, what open rate is normal, whether to use a free tool or a paid one. That's a cluster, not a list.

Tier 2: a quarter's content plan

This is the number that matters most and the one nobody wants to hear: 12 to 20 topics. That's it. If you're publishing weekly, that's 13 posts a quarter, so you need roughly 13 to 20 keyword clusters, not 500. I've watched small business owners spend three full days building an enormous keyword database and then feel so overwhelmed by it that they publish nothing for six weeks. The research took longer than the writing would have.

Tier 3: the full research pool

Where a bigger list earns its keep is at the pool stage, before you prioritise. Here you want 150 to 400 keywords across your core topics, built like this:

• Pick 5 to 10 pillar topics that map to what your business sells or solves
• For each pillar, pull 3 to 8 seed keywords using Google's own "People also ask" boxes, AlsoAsked, or Google Keyword Planner
• Expand each seed into 10 to 20 long-tail variations using autocomplete and the related searches at the bottom of a Google results page
• That gives you your 150 to 400 keyword pool, sorted by pillar
• From that pool, pick your 12 to 20 for the next 90 days based on what you can realistically write, not what has the highest search volume

The pool is the haystack. The 90-day list is the needles. Most people stop at the haystack and call it done.

A real example: the client with 40 keywords and 6 that mattered

A few years ago I worked with a small B2B software company (I'll keep the name out of it, but they sold accounting software to construction firms). Their marketing person had built a keyword list of around 900 terms using SEMrush's keyword magic tool, dumped straight into a spreadsheet, sorted by volume high to low. The top of the list was dominated by huge, generic terms like "accounting software" and "construction management," each with tens of thousands of monthly searches, and each one they had no realistic chance of ranking for as a company with a domain rating in the 20s competing against Sage and Xero.

We threw out 95% of that list. What we kept was 40 keywords tightly matched to what their actual buyer searches for, phrases like "job costing software for small contractors" and "how to invoice progress payments in construction." Low volume individually, maybe 40 to 90 searches a month each, but specific enough that anyone searching them was close to buying. Of those 40, we picked 6 to write first based on which ones matched pages they already had thin content on.

Those 6 pieces, published over eight weeks, brought in more qualified demo requests in the following quarter than the previous year of blogging combined, which had been aimed at the big generic terms nobody could win. The lesson wasn't "do more keyword research," it was "do less research, better targeted."

The uncomfortable part nobody likes admitting

Here's the bit that gets left out of most keyword research guides: the size of your keyword list has almost nothing to do with how well your content performs, and a big list often signals avoidance rather than strategy. Building a 500-term spreadsheet feels like progress. It feels like work. But it's frequently a way of postponing the harder job, which is deciding, with your name on the line, which 15 topics you're willing to bet your next three months of writing time on.

I've done this myself. Early in rebuilding my own business publicly again after a rough few years, I caught myself doing exactly this, spending an entire Sunday afternoon expanding a keyword list to 600 rows instead of sitting down to write the post I already knew I needed to write. The list-building felt productive. It wasn't. The number of keywords you have sitting in a spreadsheet is not correlated with the number of readers who will ever see your content.

If you want to see how competitive a space really is before you commit to it, it helps to understand the scale of what you're up against; there are useful ways to gauge how much competition exists in a given niche, and the same logic applies to keyword volume: a big number in front of you doesn't tell you whether you can win, it just tells you the field is crowded.

How to know your number is right for your business

The right size of your keyword list depends on three things, and none of them is "how many keywords sound impressive."

• Your publishing capacity. If you or your team can realistically write 2 posts a month, your working list should never be more than 24 topics deep for the year. Anything beyond that just sits and rots.
• Your competitive position. A brand-new site competing against established players needs to lean harder into long-tail, low-competition terms, which usually means a bigger raw pool (closer to 300 to 400) before you find your realistic 15, because so many terms get ruled out. Understanding how a smaller business competes against bigger ones changes which keywords are worth chasing in the first place.
• Your ability to track results. There's no point holding 50 target keywords if you're only checking rankings for 5 of them. Match the size of your list to what you'll monitor; I've written before about how small businesses can track keywords effectively without needing an enterprise SEO budget, and the honest answer is most small teams can watch 15 to 25 keywords at a time, tops.

What to do with your list once you have it

Once you've settled on your 12 to 20 keywords for the quarter, the job isn't finished, it's just starting. A few things I do with every list before writing a single word:

• Group keywords into clusters of 3 to 5 that can live on one page, rather than writing one thin post per keyword
• Check search intent for each cluster, because a keyword that pulls up product pages in Google means you shouldn't be writing a blog post for it at all
• Build one strong page per cluster that answers the question completely, rather than five weak pages chasing keyword variations
• If your site doesn't already have a place readers can request topics, this is also when a lot of businesses realise a simple write for me page can surface the exact questions your audience is typing into Google, which is often better keyword research than any tool

Some tools promise to shortcut this by boosting rankings for keywords you've already picked rather than helping you pick the right ones in the first place. I've looked at a few of these, including in my SERP Empire review, and the pattern holds: no tool fixes a badly chosen keyword list. It just makes a good one work faster.

For small businesses comparing options, I've set out what my AI SEO services cover. When buyers research in AI tools, being cited by Perplexity and ChatGPT puts you in the answer.

SEO writers can find more places to publish in my list of search marketing sites that welcome guest posts.

The bottom line

Stop asking how many keywords you need as if there's one universal figure. Ask instead: how many pieces of content can I write well in the next 90 days? Multiply that by 1 to 3 keywords per piece, and that's your working number, most small businesses land somewhere between 12 and 20. Build a bigger pool behind it, 150 to 400 keywords, so you're never starting from scratch each quarter. But the list you work from day to day should be short enough that you know every term on it by heart. If you can't remember your keyword list without opening the spreadsheet, it's too long.

Frequently asked questions

How many keywords should one blog post target?

One primary keyword and 3 to 5 closely related supporting keywords or questions, all covering the same core topic, is enough for a single post; targeting more than that usually means the post is trying to cover too many different intents at once.

Is a bigger keyword list always better for SEO?

No, a bigger list only helps if you can prioritise and act on it; most small businesses perform better with a tightly chosen 12 to 20 keyword quarterly plan than with an unused 500-term spreadsheet, because content quality and consistency matter more to Google than list size.

How many keywords do I need before starting content research for a new website?

Aim to build a raw pool of 150 to 400 keywords across 5 to 10 core topics before you start writing, then narrow that down to the 12 to 20 you'll publish content around in your first three months.

How often should I refresh my keyword list?

Revisit your working list every 90 days, adding new terms based on what drove traffic or leads last quarter and dropping anything you never got around to writing, so your list stays a working tool rather than an archive.