1. Who We Are & What This Policy Covers

MolecularWeightCalculator.org (“we”, “us”, “our”, or “the Site”) provides free online chemistry and science calculation tools, including — but not limited to — our molecular weight calculator, grams-to-moles converter, molarity and solution preparation tools, batch comparison tools, element mass finders, and any other calculators, converters, reference tables, or educational content we publish now or add in the future.

This Privacy Policy applies to the entire Site and every tool on it — current and future. When we launch a new calculator or feature, it is automatically covered by this policy unless we clearly state otherwise on that tool’s page.

By using the Site, you agree to the practices described here. If you do not agree, please discontinue use of the Site. This policy should be read together with our Terms & Conditions, Cookie Policy and Disclaimer.

2. How Our Calculators Handle Your Data

This is the part most visitors care about, so let’s be completely clear:

• Your inputs (formulas, masses, volumes, molarities, sample data) stay on your device.
• Your results (molar masses, conversions, recipes, tables, graphs) are generated locally and stay on your device.
• Your calculation history is saved only in your browser’s local storage (see Section 4) and can be cleared by you at any time.
• Downloads (CSV/TXT files) are created in your browser and saved directly to your device — they do not pass through our servers.
• Sharing features (WhatsApp, Facebook, X, native share) only activate when you click them, and simply open the respective service with the text you chose to share.

The same architecture applies to all related tools we add in the future: our design principle is that scientific inputs are processed locally wherever technically possible. If any future tool ever needs to send data to a server (for example, a very large database lookup), we will clearly disclose it on that tool’s page before you use it.

3. Information We Collect

3.1 Information you give us voluntarily

• Contact messages: If you email us or message us on WhatsApp, we receive your name, contact details and message content. We use these only to reply to you.
• Feedback and suggestions: Anything you choose to send us about our tools or content.

The contact form on our Contact page opens your own email application — it does not store or transmit anything through our servers.

3.2 Information collected automatically

Like almost every website, our hosting infrastructure and analytics services may automatically collect standard technical data:

• IP address (often truncated/anonymized by analytics settings)
• Browser type and version, operating system, device type and screen size
• Pages visited, time spent, referring website, and general (city/country level) location derived from IP

This data is aggregate and statistical. We do not use it to personally identify individual visitors.

3.3 Information we do NOT collect

• ❌ No account registration, usernames or passwords — the Site has no login system.
• ❌ No calculator inputs or results — they never reach us (Section 2).
• ❌ No payment information — everything on the Site is free.
• ❌ No sensitive personal data of any category.
• ❌ We never buy, sell, rent or trade personal information.

4. Cookies & Local Storage

The Site uses a small number of cookies and browser storage technologies:

Full details, including how to disable each category, are in our dedicated Cookie Policy.

5. Analytics

We may use privacy-conscious analytics services (such as Google Analytics 4 and Google Search Console) to understand — in aggregate — which tools and articles are useful, which devices visitors use, and where our traffic comes from. This helps us decide which new calculators to build and which pages to improve.

• IP anonymization is enabled where the service supports it.
• We do not link analytics data to any individual identity.
• You can opt out via our cookie consent options, browser settings, or Google’s Analytics Opt-out Browser Add-on.

6. Advertising

To keep every tool on this Site free, we may display advertising served by third-party networks such as Google AdSense. If and where ads appear:

• Ad networks may use cookies (including the Google advertising cookie) to serve ads based on your prior visits to this and other websites.
• You may opt out of personalized advertising via Google Ads Settings and aboutads.info.
• Where required by law (e.g. EU/UK), a consent banner will ask for your permission before any advertising cookies are set.

7. Third-Party Services & External Links

Our articles and tools link to reputable external resources (for example IUPAC, NIST, PubChem, Wikipedia) and offer share buttons for services like WhatsApp, Facebook and X. Please note:

• Clicking an external link or share button takes you to a service governed by its own privacy policy, which we do not control.
• Share buttons on our Site are simple links — they do not load third-party tracking scripts on our pages.
• We are not responsible for the privacy practices of external websites. We encourage you to review their policies.

8. How We Use Information

The limited information described in Section 3 is used only to:

• Operate, maintain and secure the Site and all of its tools;
• Respond to your messages and support requests;
• Understand aggregate usage so we can improve existing tools and build new ones;
• Detect and prevent abuse, spam and security threats;
• Comply with legal obligations.

9. When Information May Be Shared

We do not sell personal information — ever. Limited technical data may be processed by:

• Service providers: hosting, analytics and (if applicable) advertising partners, strictly to provide their services to us;
• Legal authorities: only if required by law, court order, or to protect the rights and safety of the Site and its users;
• Business transfer: if the Site is ever transferred to a new owner, this policy (or a stronger one) will continue to apply.

10. Data Security

We use HTTPS encryption across the entire Site, keep our software updated, and follow the principle of data minimization — the best way to protect your data is to not collect it in the first place, which is exactly how our calculators are built. However, no method of internet transmission is 100% secure, and we cannot guarantee absolute security of the limited technical data described above.

11. Data Retention

• Calculator data: retained nowhere by us — it exists only in your browser until you clear it.
• Contact emails/messages: kept only as long as needed to resolve your query, then periodically deleted.
• Analytics data: retained according to the analytics provider’s standard retention settings (typically 2–14 months), in aggregate form.

12. Your Privacy Rights (GDPR & CCPA)

Depending on where you live, you may have the right to:

• Access — request a copy of any personal data we hold about you;
• Rectification — correct inaccurate data;
• Erasure — ask us to delete your data (e.g. old contact emails);
• Restriction & objection — limit or object to certain processing;
• Portability — receive your data in a portable format;
• Withdraw consent — at any time, where processing is based on consent (e.g. cookies);
• Non-discrimination (CCPA) — we will never treat you differently for exercising your rights. We do not “sell” or “share” personal information as defined by the CCPA/CPRA.

To exercise any of these rights, contact us using the details in Section 16. We respond to verified requests within 30 days. EU/UK residents also have the right to lodge a complaint with their local supervisory authority.

13. Children’s Privacy

Our tools are educational and safe for students of all ages. We do not knowingly collect personal information from children under 13 (or the equivalent minimum age in your jurisdiction). The Site requires no registration, so children can use every calculator without providing any personal data. If you believe a child has sent us personal information (e.g. via email), contact us and we will delete it promptly.

14. International Users

The Site is operated from Pakistan and may use hosting, analytics and advertising services located in other countries (including the United States and the European Union). By using the Site, you understand that the limited technical data described in this policy may be processed in countries with different data protection laws than your own. Where required, we rely on appropriate safeguards such as the providers’ standard contractual clauses.

15. Changes to This Policy

As we add new tools and features, we may update this Privacy Policy. Material changes will be reflected on this page with an updated effective date at the top. We encourage you to review this page occasionally. Continued use of the Site after changes means you accept the updated policy.

16. How to Contact Us

Questions, concerns, or a privacy rights request? We’re easy to reach: