These are free calculators and checkers for the questions that come up again and again when a UK business runs some of its own SEO or advertising: whether a title tag will be cut off in Google, whether a campaign makes money once margin is taken into account, and whether a new landing page really converted better or last week was simply a good week. Each tool does one job, works with your own numbers and gives you an answer in a few seconds, without an account or an email address.
They sit alongside the free guides and checklists rather than replacing them. A guide explains how something works and what order to do it in. A tool answers one narrow question, usually the one you need settled before you publish a page, launch a campaign or agree a budget.
Search and content tools
For pages you are writing, rewriting or moving.
- Checker
Title tag and meta description checker
Paste a title and description and see a preview of the search result, with a character count and an estimated pixel width for each. Google trims snippets by display width rather than by a fixed number of characters, so a title full of capitals or wide letters can be cut short well before 60 characters.
- Checker
Readability and keyword density checker
Paste a draft to get its word and sentence counts, a reading-ease score, a grade level and an estimated reading time, plus the phrases you repeat most. It is a quick way to catch a keyword that has been forced into every second sentence.
- Tool
Keyword clustering tool
Paste a keyword list and it groups terms that share words, so you can plan one page per group instead of several pages chasing the same search. It groups by wording, not by checking what Google shows for each term, so read the groups before you build pages from them.
- Tool
Redirect map builder
Paste old and new URLs in pairs and get Apache or Nginx rules, or a CSV for a WordPress redirect plugin. It also flags redirect chains and loops, which are easy to create by accident when a site has been moved more than once.
Google Ads and paid social tools
For building campaigns and planning spend on Google, Facebook and Instagram.
- Tool
Keyword match type tool
Paste a keyword list and get broad, phrase and exact match versions formatted to paste straight into Google Ads, with an optional negative keyword list in phrase or exact match. It saves typing quotation marks and square brackets by hand, which is where most formatting errors creep in.
- Tool
Ad copy character counter
Draft responsive search ad headlines and descriptions, or Facebook and Instagram ad text, and see what fits before you open the ad editor. Writing in the counter first means you are not cutting words down inside the platform under time pressure.
- Calculator
Reach and frequency calculator
Enter a budget, the CPM you expect, a target frequency, the audience size and the campaign length to see the impressions you can buy, roughly how many people you will reach and the daily spend. If the budget buys more impressions than the audience can absorb, it shows how far frequency climbs above your target. It is most useful for local campaigns, where an audience limited to a few London postcodes or one market town is small enough for frequency to climb quickly.
Measurement and profitability tools
For checking whether marketing is tracked properly and whether it pays.
- Tool
UTM link builder
Build a tagged link for an email, social post, QR code or partner website, so the visits arrive in GA4 under the right source and channel rather than in Direct or Unassigned. Agree one naming convention and keep to it, because GA4 treats “Newsletter” and “newsletter” as two different sources. The builder lower-cases what you type, but links tagged by hand elsewhere will not be.
- Calculator
ROAS and ROI calculator
Enter ad spend, the revenue from those ads, your gross margin and any management fees to see return on ad spend, profit, ROI and the break-even ROAS. The break-even figure is the one most owners do not have: at a 40% gross margin, every £1 of ad spend needs to bring in £2.50 of revenue before fees just to stand still.
- Calculator
LTV and CAC calculator
Compare what a customer is worth over their whole relationship with you against what it costs to win them, and see how many months it takes to earn the acquisition cost back. It suits businesses with repeat purchases or contracts, where judging ads on the first sale alone makes them look worse than they are.
- Calculator
A/B test significance calculator
Enter visitors and conversions for two versions of a page or ad and choose a confidence level. It shows each conversion rate, the relative change, a p-value and a confidence interval, which together tell you whether the difference is likely to be real or within the range you would expect from chance. The glossary entry on statistical significance explains the idea in plain terms.
Where to start
If you are about to put money into ads, start with the break-even ROAS. Knowing the minimum return a campaign has to reach makes every later decision about bids and budgets easier, and it is a number you can work out before a single click is bought.
If you are relaunching or restructuring a website, build the redirect map before anything else and work through the website launch SEO checklist alongside it. Old URLs left without a redirect are one of the commonest reasons a relaunched site loses the search visibility it had.
If GA4 shows a lot of Direct traffic on the days you send a newsletter or post on social media, the UTM builder is the fix. Untagged links from email apps and social apps often arrive with no referrer, so GA4 cannot tell where they came from.
Getting reliable answers from them
The tools only know what you type in, so most odd results come from the inputs. A few habits keep them honest:
- Use the same period for every figure. Spend from one month and revenue from a quarter gives a ROAS that means nothing.
- Keep VAT consistent. If your revenue figures include VAT and your costs do not, returns look a fifth better than they are at the standard 20% rate. For a VAT-registered business, the simplest rule is to use figures excluding VAT throughout.
- Enter money in pounds and the results come back in pounds. The calculators do the arithmetic; they do not convert currencies.
- Treat platform limits as a guide. Google and Meta change character limits and how results are displayed from time to time, so check the final version in the platform before it goes live.
None of the tools connects to your Google Ads, Meta or GA4 accounts. They give you a fast, private estimate, not an audit of what is actually happening in those accounts.
When a calculator is not enough
A tool answers the question you put to it. If the ROAS calculator shows a campaign running below break-even, it cannot tell you whether the cause is the targeting, the landing page, the bidding or tracking that undercounts sales. Finding that out means looking inside the account, which is the work I do in Google Ads management and the wider SEO services.
If you were looking for the paid software I use for keyword research, crawling and reporting, that is listed separately on the page about the tools I use for client work.