Privacy Policy

Welcome to VastCalc ("we," "us," or "our"). VastCalc operates the website located at vastcalc.com (the "Service"). This Privacy Policy describes how we collect, use, disclose, and protect your personal information when you access or use our Service.

By using VastCalc, you agree to the collection and use of information in accordance with this Privacy Policy. If you do not agree with the terms of this policy, please do not access or use our Service.

We collect different types of information depending on how you interact with our Service:

We use the information we collect for the following purposes:

• To provide, maintain, and improve our Service, including delivering calculator functionality and personalized features
• To manage your account, including authentication and access to saved favorites and calculation history
• To communicate with you regarding your account or changes to our Service
• To monitor usage patterns and fix performance problems
• To detect, prevent, and address technical issues or security threats

VastCalc uses cookies and similar technologies to operate and provide our Service. Specifically, we use:

• Session cookies: Essential cookies required for authentication and maintaining your logged-in state
• Preference cookies: Cookies that remember your settings, such as theme preference (light or dark mode)

We do not use third-party advertising cookies or tracking cookies. You may configure your browser to refuse cookies, but doing so may limit your ability to use certain features of the Service.

Your personal information is stored in a secure PostgreSQL database hosted on infrastructure that we control. We implement industry-standard security measures to protect your data, including:

• Encryption of all data in transit via HTTPS/TLS
• Secure password hashing using modern cryptographic algorithms
• Access controls limiting data access to authorized systems only
• Regular security reviews of our infrastructure and codebase

No method of electronic transmission or storage is completely secure. We take reasonable steps to protect your information, but we cannot guarantee absolute security. If a security incident affects your data, we will notify you.

We do not sell, trade, or rent your personal information to third parties. We may disclose your information only in the following circumstances:

• Legal obligations: When required by law, regulation, legal process, or enforceable governmental request
• Protection of rights: When necessary to protect the rights, property, or safety of VastCalc, our users, or the public
• Service providers: With trusted service providers who assist in operating our Service (e.g., hosting, content delivery), subject to confidentiality obligations

Depending on your jurisdiction, you may have the following rights regarding your personal data:

• Access: Request a copy of the personal data we hold about you
• Correction: Request correction of inaccurate or incomplete personal data
• Deletion: Request deletion of your personal data and account
• Data portability: Request a copy of your data in a structured, machine-readable format
• Withdrawal of consent: Withdraw your consent to data processing at any time, where consent is the legal basis for processing

To exercise any of these rights, please contact us at [email protected]. We will respond to your request within 30 days.

Our Service may contain links to third-party websites or services that are not operated by us. We have no control over and assume no responsibility for the content, privacy policies, or practices of any third-party sites or services. We encourage you to review the privacy policy of every site you visit.

Our Service is delivered through Cloudflare's content delivery network, which may process certain technical data (such as IP addresses) in accordance with their own privacy policy to provide security and performance optimization.

VastCalc calculators can be embedded on other websites via an iframe or our lightweight JavaScript snippet. When someone interacts with one of those embedded calculators, we record a small amount of usage data so we can understand which calculators are most useful and on what kinds of sites.

What we collect from embedded calculator views:

• The calculator slug and category
• The inputs you enter and the outputs the calculator returns (only when you click "Calculate")
• The origin of the page hosting the iframe (e.g. https://example.com), when your browser exposes it
• An opaque per-tab session ID (kept in sessionStorage)
• A salted SHA-256 hash of your IP address, used for deduplication and abuse prevention. We do not store the raw IP address.
• The user-agent string sent by your browser

We do not set cookies on the host page, do not include any third-party tracking scripts, and do not link this data to your VastCalc account (if you have one). If the publisher who embedded the calculator wants to opt out, they can append ?notrack=1 to the embed URL or set data-notrack="1" on the script tag. The renderer skips the beacon entirely when that flag is set.

VastCalc accounts are not available to children under the age of 13. In compliance with the Children's Online Privacy Protection Act (COPPA), we do not knowingly collect, store, or process any personal information from children under 13.

When creating an account, all users must provide their date of birth so that we can verify they meet the minimum age requirement. Date of birth is used solely for this verification and is not retained after the account is created. Accounts that indicate an age below 13 are blocked from being created.

The calculators on VastCalc themselves are free to use without an account at any age and do not require any personal information. Children under 13 may use the calculators for educational purposes; we simply do not create user profiles, save favorites, or store calculation history for them.

If we become aware that we have inadvertently collected personal data from a child under 13, we will take steps to delete such information promptly. If you are a parent or guardian and you believe that a child under 13 has provided us with personal information, please contact us immediately at [email protected] and we will delete the account and associated data.

We retain your personal information for as long as your account is active or as needed to provide you with our Service. If you delete your account, we will delete your personal data, including your calculation history and favorites, within 30 days. We may retain certain information as required by law or for legitimate business purposes, such as resolving disputes or enforcing our agreements.

We may update this Privacy Policy from time to time to reflect changes in our practices or applicable laws. When we make material changes, we will update the "last updated" date at the top of this page. Check back periodically to see how your information.

Your continued use of the Service after any changes to this Privacy Policy constitutes your acceptance of the updated terms.

If you have any questions, concerns, or requests regarding this Privacy Policy or our data practices, please contact us at:

[email protected]