Privacy Policy

Last updated: 2026-07-10

This policy describes how we (“we”, “us”) collect, use, and protect your personal data when you visit knitcalcs.uk. It is written to comply with the UK General Data Protection Regulation (UK GDPR), the Data Protection Act 2018, and the Privacy and Electronic Communications Regulations (PECR).

1. Data controller

The operator of this site is the data controller for personal data processed through it.

2. What we collect

We collect only the minimum data needed to run and improve the site.

2.1 Data you provide

Calculator inputs. Numbers and selections you type into calculator forms are processed in your browser. They are not sent to our servers unless you choose to report an issue via the feedback buttons, in which case your inputs for that calculator are attached so we can reproduce the problem. They are stored in your device’s localStorage only if you opt in (see §3).
Feedback. If you use the feedback buttons (helpful vote, report an issue, request a calculator, suggest a feature, general comments), we receive your message, the page address, coarse device type and viewport size, your country, and — for issue reports only — the calculator inputs you had entered. Feedback is voluntary and anonymous unless you choose to include contact details, and is kept for up to 24 months.
Enquiries. If you contact us, we retain the message you send and any details it contains, solely to answer you.

2.2 Data collected automatically

Aggregate usage statistics (first-party, no consent needed). We operate our own counter that records, in aggregate only, which pages are used, when, and from which country. When your browser requests a page it automatically sends your IP address and browser type; our system immediately converts these into an anonymous code (a one-way hash salted per site and rotated every 24 hours) used only to avoid double-counting within a day, then discards the originals. We store only totals (e.g. “this calculator: N visits”). We never build individual profiles, never link data across our sites or across days, never share it for third-party purposes, and store nothing on your device for this. You can object at any time using the toggle in the cookie banner or on our Cookie Policy page; your choice is remembered on your device.
Google Analytics 4 (GA4) — statistical purposes only. Measures page-views and feature usage solely so we can improve these calculators, under the PECR statistical-purposes exception (Data (Use and Access) Act 2025; ICO guidance April 2026). We run GA4 with Google acting strictly as our processor: all Google data-sharing settings are off, no advertising features, no Google Signals, minimum (2-month) data retention, and Google may not use the data for its own purposes or link it with other data. GA4 sets _ga cookies with a pseudonymous client ID. You can switch this off at any time with the “Anonymous usage statistics” toggle (first-visit notice or Cookie Policy page) — opting out stops collection before any data is sent and deletes existing GA cookies.
Microsoft Clarity (session replay) — only if you allow it. Records anonymised session replays and heatmaps to help us improve usability. Loads only after you actively choose “Allow replay” in the first-visit notice. Microsoft is our processor; see Microsoft’s privacy statement.
Server logs. Cloudflare Pages (our host) may retain short-lived access logs for security and abuse prevention. These are not used for user profiling.

3. Local storage on your device

Some calculators can remember preferences on your own device for convenience:

Calculation history. If you run a calculator, the calculator name, a short result summary, and the page URL are saved in your browser’s localStorage so you can revisit it. Up to 100 entries are kept, newest first. Nothing is sent to our servers.
Unit preferences. If you switch between cm/inches or g/oz on a calculator, the choice is remembered on your device.
Privacy-notice dismissal and opt-out. Whether you have seen the first-visit privacy notice, your session-replay choice, and your “Anonymous usage statistics” opt-out if you exercise it.

You can clear any of this at any time: browser Settings → Privacy → Clear site data, or the “Clear history” button on the calculator page.

4. Legal basis for processing

Statistical-purposes exception + legitimate interests (PECR Sch A1 para 5; UK GDPR Art. 6(1)(f)) for the first-party usage counter and Google Analytics 4 in processor-only configuration (§2.2) — both used solely to improve the service, with a free opt-out toggle at any time.
Consent (UK GDPR Art. 6(1)(a) + PECR reg. 6) for session replay (Microsoft Clarity) only — it never runs unless you actively allow it, and you can withdraw by clearing this site’s storage.
Legitimate interest (UK GDPR Art. 6(1)(f)) for server security logs, abuse prevention, and the first-party aggregate usage counter (§2.2), which also relies on the statistical-purposes exception in PECR Schedule A1 paragraph 5 — you can object at any time via the toggle in the cookie banner or on the Cookie Policy page.
Performance of a contract (UK GDPR Art. 6(1)(b)) for responding to enquiries you send us.

5. Who we share data with

Personal data is shared only with the joint processors named in §2.2 (Google, Microsoft, Cloudflare). We do not sell personal data. We do not use personal data for advertising-targeting.

6. International transfers

Google, Microsoft, and Cloudflare may process data in the USA and other countries under Standard Contractual Clauses or equivalent UK safeguards (UK GDPR Chapter V).

7. Retention

First-party usage counter: raw IP address and browser type are never written to storage (hashed then discarded in-request); the anonymous aggregate totals contain no personal data.
Feedback messages: up to 24 months.
GA4 data: 2 months (minimum retention setting; the _ga cookie itself expires after 13 months).
Clarity session data (only if you allowed replay): up to 13 months (Microsoft default).
Your localStorage: kept on your device until you clear it.
Enquiry messages: up to 24 months after last correspondence.

8. Your rights

Under UK GDPR you have the right to:

access the personal data we hold about you (Art. 15);
rectify inaccurate personal data (Art. 16);
have personal data erased (Art. 17);
restrict processing (Art. 18);
port your data to another provider (Art. 20);
object to processing based on legitimate interests (Art. 21);
withdraw consent at any time without detriment;
complain to the Information Commissioner’s Office (ICO).

This site requires no account and stores no personal data on our servers — calculator inputs stay in your browser (see §2), so in most cases we hold no personal data to access, rectify, port or erase. The only personal data processed is the analytics/measurement data handled by our processors (Google, Microsoft) and only after you opt in. You can exercise your rights over that data directly:

withdraw or change your consent at any time using the cookie banner — this stops further analytics collection immediately;
use Google’s and Microsoft’s own privacy controls to access or delete the analytics data they hold as our processors;
contact, or request assistance from, the ICO (link above) if you are unable to resolve a request through the routes above. Where a request reaches us we respond within one calendar month (Art. 12(3)).

9. Security

The site is served over HTTPS from Cloudflare with standard security headers (CSP, HSTS, X-Content-Type-Options, Referrer-Policy, Permissions-Policy). Because calculations run in your browser, calculator inputs never traverse our servers and are not at risk of transit interception.

10. Changes to this policy

We update this policy when the law, our processors, or our practices change. The “last updated” date above reflects the most recent revision.