Privacy Policy

The short version: the calculators run entirely in your browser. The numbers you type into them are never sent to us, never stored on our servers, and never shared. There is nothing to log in to.

1. What we do not collect

We do not require an account to use the free calculators. We do not receive, store, or process the values you enter into any calculator — all computation happens locally on your device. We do not sell or rent personal data, because we do not build personal profiles in the first place.

2. What we do collect

To keep the site running and understand which calculators are useful, we use privacy-respecting, aggregate analytics that do not use invasive cookies and do not track you across other websites. This may include coarse information such as page views, approximate country, referring site, and device type. It is not tied to your identity.

3. Cookies & local storage

The free calculators work without cookies. If you use optional features such as saving a scenario, we may store that data locally in your browser (local storage) so it is available when you return. You can clear it at any time from your browser settings.

4. If you contact us

When you email us or use a contact form, we receive the information you choose to send (such as your name, email address and message) so we can reply. We keep it only as long as needed to handle your enquiry.

5. Third-party services

We rely on reputable infrastructure providers to host and deliver the site. These providers may process limited technical data (such as IP address) as part of serving the page securely. We choose providers that support privacy-respecting configurations.

6. Your rights

Depending on where you live, you may have rights to access, correct, or delete personal data we hold about you. Since we hold very little, this is usually limited to correspondence you have sent us. Email us to exercise any right.

7. Children

The Service is intended for a general and professional audience and is not directed at children under 13.

8. Changes & contact

We may update this policy as the Service evolves. Questions or requests? Email contact@bottleneckcalculators.org.