Privacy Policy

We've kept this as plain and specific as possible. It covers exactly what data we collect, why, and who sees it — nothing more.

Last updated: April 2026  ·  Jurisdiction: England and Wales

Plain English Summary
  • We do not sell your data to anyone, ever.
  • Analytics only runs if you accept — and you can withdraw that at any time.
  • The calculators do not collect or store any of the numbers you enter.
  • No account or sign-up is required to use any tool on the site.

1. Who we are

Material Calculator (materialcalculator.co.uk) is a free online tool suite providing construction and DIY material calculators for users in the United Kingdom. The site is operated as an independent service. For data protection purposes, the operator of this site is the data controller.

Contact: hello@materialcalculator.co.uk

2. What data we collect and why

We collect a minimal amount of data, split into two clear categories.

2a — Data we always collect (essential)
What Why Storage
Cookie consent choice Remembers whether you accepted or rejected analytics so we don't ask again Cookie (12 months)
Per-service consent state Stores your individual preferences for Google Analytics and Microsoft Clarity separately Cookie (12 months)
Theme preference Remembers your light/dark mode choice localStorage (no expiry)
2b — Data we collect only with your consent (analytics)
Service What it collects Purpose
Google Analytics 4 Pages visited, session duration, approximate location (country/region), device type, referral source Understand which calculators are most used and how people find the site
Microsoft Clarity Anonymised session recordings, heatmaps, click and scroll patterns Understand where users get stuck in calculators so we can improve usability
Important: The numbers you enter into our calculators — dimensions, quantities, depths — are processed entirely in your browser and are never sent to our servers or to any analytics platform. We cannot see what you calculate.

3. Legal basis for processing

Under UK GDPR, we rely on the following legal bases:

  • Legitimate interests — storing your consent choice and theme preference so the site functions correctly across visits. These are necessary for the service to work as expected and are proportionate to any privacy impact.
  • Consent — for Google Analytics 4 and Microsoft Clarity. These only activate when you explicitly accept analytics via the cookie banner, and only for the specific services you enable. You can withdraw consent at any time.

4. Cookies in detail

The following cookies may be set on your device, depending on your consent choices.

Essential cookies (always set)
Name Purpose Duration
cc_cookie Stores your consent choices (categories and per-service toggles). Set by CookieConsent v3. 12 months
mc-theme Stores your light/dark mode preference. Stored in localStorage, not a cookie. Until cleared
Analytics cookies (only with consent)
Name Set by Purpose Duration
_ga, _ga_* Google Analytics 4 Distinguishes unique visitors and sessions 2 years
_gid Google Analytics 4 Distinguishes users within a 24-hour session 24 hours
_clsk Microsoft Clarity Connects page views within a session 1 day
_clck Microsoft Clarity Persists the Clarity User ID and session 1 year

If you withdraw consent for an analytics service, all cookies belonging to that service are automatically deleted from your browser. Google Analytics and Microsoft Clarity can be toggled independently via the cookie preferences panel.

5. Google Consent Mode V2

We implement Google Consent Mode V2. This means Google Tag Manager is loaded on all page visits, but Google Analytics operates in different modes depending on your consent choice:

  • Consent granted — GA4 sets cookies and collects full session data attributed to your device.
  • Consent denied — GA4 operates in cookieless mode. No cookies are set and no personal identifier is collected. Google may use aggregated, modelled data to estimate traffic patterns, but this cannot be linked to you individually.

Google Tag Manager itself is lazy-loaded — it only initialises after your first interaction with the page (mouse movement, scroll, or tap), or after 5 seconds if no interaction occurs. This minimises its impact on page load performance.

6. Managing your consent

You can review and change your cookie preferences at any time using the link below. The preferences panel lets you accept or reject Google Analytics and Microsoft Clarity individually.

When you withdraw consent, the relevant analytics cookies are automatically deleted. Withdrawing consent does not affect the lawfulness of processing that took place before withdrawal.

You can also block or delete cookies at any time through your browser settings. Note that blocking essential cookies may affect how the site displays (theme preference will not be remembered).

7. Data we do not collect

To be explicit about what we do not do:

  • We do not collect your name, email address, or any contact information unless you voluntarily email us.
  • We do not collect or store the values you enter into any calculator. All calculations happen in your browser.
  • We do not build user profiles or track you across other websites.
  • We do not sell, share or license your data to any third party for commercial purposes.
  • We do not use your data to make automated decisions that affect you.

8. Third-party services

When you accept analytics, data is processed by the following third parties under their own privacy policies:

  • Google LLC — Google Analytics 4 and Google Tag Manager. Data may be processed in the United States under Google's Standard Contractual Clauses. Google Privacy Policy →
  • Microsoft Corporation — Microsoft Clarity. Data may be processed in the United States. Microsoft Privacy Statement →

No other third-party scripts, fonts loaded from external CDNs, or tracking services are used on this site. Our fonts (DM Sans and DM Mono) are self-hosted and do not make external requests.

9. Data retention

Data retention periods for each category:

  • Consent preferences — stored in a browser cookie for 12 months, then automatically expire. Deleted immediately if you clear your cookies.
  • Google Analytics data — retained in Google Analytics for 14 months from the date of collection, as configured in our GA4 property settings. Raw event data in BigQuery (if exported) follows the same retention schedule.
  • Microsoft Clarity session recordings — retained by Clarity for 30 days from the date of recording.
  • Emails you send us — retained for as long as necessary to handle your query, and deleted within 12 months of the last correspondence unless there is a legal reason to retain them.

10. Your rights under UK GDPR

As a UK resident, you have the following rights in relation to your personal data:

  • Right of access — you can request a copy of the personal data we hold about you.
  • Right to rectification — you can ask us to correct inaccurate data.
  • Right to erasure — you can ask us to delete your personal data where we have no compelling reason to continue processing it.
  • Right to restrict processing — you can ask us to limit how we use your data in certain circumstances.
  • Right to object — you can object to processing based on legitimate interests.
  • Right to withdraw consent — you can withdraw analytics consent at any time via the cookie preferences panel. This does not affect prior processing.
  • Right to lodge a complaint — you have the right to complain to the Information Commissioner's Office (ICO) if you believe your data has been handled unlawfully. ICO complaints →

In practice, because we collect minimal data and analytics cookies are session-based and anonymised, we hold very little that constitutes personal data about any individual visitor. For most requests, withdrawing consent and clearing your browser cookies will satisfy your rights immediately without needing to contact us.

To exercise any of the above rights, contact us at hello@materialcalculator.co.uk. We will respond within one calendar month.

11. Children

This website is not directed at children under 13. We do not knowingly collect personal data from children. If you believe a child has provided personal data to us, please contact us and we will delete it promptly.

12. Changes to this policy

We may update this Privacy Policy from time to time, for example if we add new analytics tools, change third-party providers, or if the law changes. The date at the top of this page shows when it was last updated. Material changes will be noted in the update date. Continued use of the site after changes constitutes acceptance of the updated policy.

13. Contact

For any privacy-related questions, requests, or complaints, please contact us at hello@materialcalculator.co.uk. We aim to respond to all enquiries within 5 working days.

If you are not satisfied with our response, you have the right to escalate to the Information Commissioner's Office at ico.org.uk.

Read our Terms of Use All Calculators