BMI Calculator NHS (bmicalculatornhs.co.uk) is committed to protecting your privacy and handling your personal data with transparency, care, and full compliance with the UK General Data Protection Regulation (UK GDPR) and the Data Protection Act 2018. This Privacy Policy explains in detail what information we collect, why we collect it, how we use it, and what rights you have over your data.
We want to be especially clear about one important point: the health data you enter into our BMI calculators — your height, weight, age, and gender — is processed entirely within your browser and is never transmitted to or stored on our servers. Your health information remains private to you at all times.
Please read this Privacy Policy carefully. By using our website, you acknowledge that you have read and understood how we handle your information. If you have any questions, please contact us at info@bmicalculatornhs.co.uk.
📋 Contents
1. Who We Are
BMI Calculator NHS operates the website at bmicalculatornhs.co.uk. We are an independent health information website providing free, NHS-aligned BMI and health calculation tools for UK adults and families. We are not affiliated with or endorsed by NHS England or any NHS Trust.
For the purposes of UK GDPR, we act as the data controller for any personal data collected through this website. Our contact details for data protection matters are:
- Email: info@bmicalculatornhs.co.uk
- Website: bmicalculatornhs.co.uk
2. Information We Collect
We collect different types of information depending on how you interact with our website:
2.1 Calculator Data (Health Information)
🔒 Your health data is 100% private. All BMI calculations — height, weight, age, gender — are processed locally in your browser using JavaScript. This data is never sent to, transmitted to, or stored on our servers. It disappears when you close or refresh the page.
Our tools — including the BMI Calculator, Visual BMI Calculator, Child Growth Chart Calculator, Ideal Weight Calculator, Percentile Calculator, and Baby Weight Percentile Calculator — process your inputs entirely on your device. No health data ever leaves your browser.
2.2 Analytics Data (Anonymous)
With your consent, we collect anonymous website usage data including:
- Pages visited and time spent on each page
- Browser type and version
- Device type (mobile, tablet, desktop)
- Approximate geographic location (country/region level only — not precise location)
- Referring website (how you found us)
- Screen resolution and operating system
This data is collected via Google Analytics and is fully anonymised — it cannot be used to identify you personally.
2.3 Contact Form Data
When you submit our contact form, we collect:
- Your name
- Your email address
- The subject and content of your message
- The date and time of submission
This information is used solely to respond to your enquiry and is not used for marketing purposes without your explicit consent.
2.4 Technical Data (Automatically Collected)
When you visit our website, our web server automatically records:
- Your IP address (anonymised for analytics purposes)
- The date and time of your visit
- The URL of the page requested
- HTTP status codes
This data is used for security monitoring and to diagnose technical issues. Server logs are retained for a maximum of 30 days.
2.5 Cookie Data
We use cookies to remember your preferences and to collect analytics data with your consent. See Section 4 (Cookies) for full details.
3. How We Use Your Information
We use the information we collect for the following specific purposes:
| Purpose | Type of Data | Legal Basis |
|---|---|---|
| Providing and operating our BMI calculator tools | Calculator inputs (browser-only) | Legitimate interests |
| Responding to contact form enquiries | Name, email, message | Contract / Legitimate interests |
| Analysing website usage to improve user experience | Anonymous analytics data | Consent |
| Security monitoring and fraud prevention | IP address, server logs | Legitimate interests |
| Complying with legal obligations | Any relevant data | Legal obligation |
| Displaying relevant advertisements | Cookie data (with consent) | Consent |
We do not sell your personal data to third parties. We do not use your data for automated decision-making or profiling that produces legal or similarly significant effects.
4. Cookies and Tracking Technologies
Cookies are small text files placed on your device when you visit a website. We use cookies for the following purposes:
4.1 Essential Cookies
These cookies are necessary for the website to function correctly and cannot be disabled:
- cookie_consent: Remembers whether you have accepted or declined our cookie policy (expires: 12 months)
- Session cookies: Maintain basic website functionality during your visit (expires: when browser closes)
4.2 Analytics Cookies (With Consent)
With your consent, we use Google Analytics to understand how visitors use our website:
- _ga: Distinguishes unique users (expires: 2 years)
- _ga_[ID]: Maintains session state (expires: 2 years)
- _gid: Distinguishes users (expires: 24 hours)
Google Analytics data is anonymised — IP addresses are truncated and no personally identifiable information is collected. Google's data processing terms apply. You can opt out of Google Analytics at all times via Google's opt-out tool.
4.3 Advertising Cookies (With Consent)
With your consent, we may use Google AdSense to display relevant advertisements. AdSense uses cookies to serve personalised ads based on your recent browsing activity. You can manage your Google ad settings at adssettings.google.com.
4.4 Managing Cookies
You can manage your cookie preferences at any time by:
- Using our cookie consent banner when you first visit the site
- Adjusting your browser settings to block or delete cookies
- Using your browser's private/incognito mode
Note: disabling analytics or advertising cookies will not affect your ability to use any of our BMI calculator tools.
5. Legal Basis for Processing
Under UK GDPR, we must have a valid legal basis for processing personal data. We rely on the following bases:
- Consent (Article 6(1)(a)): For analytics cookies, advertising cookies, and any optional marketing communications. You can withdraw consent at any time.
- Legitimate Interests (Article 6(1)(f)): For operating our website, responding to contact enquiries, and security monitoring — where our interests do not override your rights and freedoms.
- Legal Obligation (Article 6(1)(c)): Where we are required by law to process your data.
We never process special category data (such as health data) on our servers. All health-related calculator inputs are processed entirely in your browser.
6. Data Sharing and Third Parties
We do not sell your personal data. We may share limited data with the following trusted third-party service providers:
| Service | Purpose | Data Shared | Privacy Policy |
|---|---|---|---|
| Google Analytics | Website analytics | Anonymous usage data | View |
| Google AdSense | Displaying advertisements | Cookie data (with consent) | View |
| Cloudflare | Performance & security CDN | IP address, request data | View |
| Hosting Provider | Website hosting | Server log data | Provider policy applies |
We may also disclose your data where required by law, court order, or regulatory authority — for example, to comply with a legal obligation or to protect the rights, property, or safety of our users.
7. Data Retention
We retain personal data only for as long as necessary for the purposes described in this policy:
- Calculator health data: Not retained — processed in your browser only, never stored
- Contact form submissions: Retained for up to 12 months after your enquiry is resolved, then securely deleted
- Analytics data: Retained for up to 26 months (Google Analytics default) then automatically deleted
- Server logs: Retained for up to 30 days for security purposes, then automatically deleted
- Cookie consent records: Retained for 12 months
When retention periods expire, data is securely deleted or anonymised in a way that it can no longer be attributed to any individual.
8. Data Security
We take data security seriously and implement appropriate technical and organisational measures to protect your personal data against unauthorised access, disclosure, alteration, or destruction. Our security measures include:
- HTTPS encryption: All data transmitted between your browser and our website is encrypted using TLS (HTTPS)
- Cloudflare protection: DDoS mitigation, firewall rules, and security monitoring via Cloudflare
- No server-side health data storage: Your BMI and health calculator inputs are never transmitted to our servers
- Regular security reviews: We regularly review our security practices and update them as needed
- Limited data access: Access to any personal data we hold is strictly limited to authorised personnel
🛡️ Important: While we implement strong security measures, no internet transmission is 100% secure. If you contact us by email, please be aware that email is not inherently secure. Never send sensitive health or financial information via email.
In the unlikely event of a personal data breach that is likely to result in a risk to your rights and freedoms, we will notify the Information Commissioner's Office (ICO) within 72 hours as required by UK GDPR, and will notify affected individuals where required.
9. Your Rights Under UK GDPR
Under the UK General Data Protection Regulation, you have the following rights regarding your personal data:
Right of Access
Request a copy of the personal data we hold about you (Subject Access Request).
Right to Rectification
Request correction of inaccurate or incomplete personal data we hold.
Right to Erasure
Request deletion of your personal data ("right to be forgotten") in certain circumstances.
Right to Restriction
Request that we restrict processing of your data in certain circumstances.
Right to Portability
Receive your personal data in a structured, machine-readable format.
Right to Object
Object to processing of your data based on legitimate interests or for direct marketing.
Right to Withdraw Consent
Withdraw consent for analytics or advertising cookies at any time — without affecting past processing.
Right to Complain
Lodge a complaint with the ICO (Information Commissioner's Office) if you believe we have mishandled your data.
To exercise any of your rights, please contact us at info@bmicalculatornhs.co.uk. We will respond to all requests within 30 days as required by UK GDPR.
If you are not satisfied with our response, you have the right to complain to the Information Commissioner's Office (ICO): ico.org.uk | Helpline: 0303 123 1113
10. Children's Privacy
Our website includes tools specifically designed to help parents and healthcare professionals monitor children's growth — including the Child Growth Chart Calculator UK, Percentile Calculator UK, and Baby Weight Percentile Calculator UK.
These tools are intended to be used by parents, guardians, and healthcare professionals on behalf of children — not directly by children themselves. We do not knowingly collect personal data directly from children under the age of 13.
All health data entered for children (including weight, height, age, and gender) is processed entirely within your browser and is never stored on our servers. No child health data is transmitted to or retained by us in any form.
If you believe that a child has provided us with personal data without appropriate parental consent, please contact us immediately at info@bmicalculatornhs.co.uk and we will take steps to delete any such data.
11. External Links
Our website contains links to external websites, including NHS.uk, CDC.gov, and other health information resources. These external sites have their own privacy policies, which we have no control over and take no responsibility for.
We encourage you to review the privacy policy of any external website you visit via a link from our site. The presence of a link on our website does not constitute an endorsement of that website's privacy practices.
12. Changes to This Privacy Policy
We may update this Privacy Policy from time to time to reflect changes in our practices, technology, or legal requirements. When we make significant changes, we will:
- Update the "Last Updated" date at the top of this page
- Where practical, notify users via a notice on our website
We encourage you to review this Privacy Policy periodically. Your continued use of our website after changes are posted constitutes your acceptance of the updated policy. If you do not agree to the updated policy, please discontinue using our website.
Previous versions of this Privacy Policy are available on request by contacting us at info@bmicalculatornhs.co.uk.
13. Contact Us
If you have any questions, concerns, or requests regarding this Privacy Policy or how we handle your personal data, please do not hesitate to contact us. We aim to respond to all privacy-related enquiries within 5 business days.
- Email: info@bmicalculatornhs.co.uk
- Website: bmicalculatornhs.co.uk
- Data Controller: BMI Calculator NHS
For complaints about how we handle your personal data, you also have the right to contact the Information Commissioner's Office (ICO) directly:
- Website: ico.org.uk
- Helpline: 0303 123 1113
- Address: Information Commissioner's Office, Wycliffe House, Water Lane, Wilmslow, Cheshire, SK9 5AF
Have a Privacy Question?
We're committed to transparency. Contact us and we'll respond within 5 business days.
📧 info@bmicalculatornhs.co.ukRelated Legal Documents
This Privacy Policy should be read alongside our other legal documents:
- Terms of Service — rules and conditions for using our website and tools
- Disclaimer — important information about the nature of our health information tools
You may also find our health calculation tools useful:
- Visual BMI Calculator — NHS-aligned BMI calculation with body shape illustration
- Ideal Weight Calculator UK — personalised healthy weight range
- Child Growth Chart Calculator UK — NHS growth chart for children 0–18