About this calculator

I hope you enjoy this tool and that it is useful to you! I created this site and I maintain it on my free time. Also, server cost me a few dollars every month, so if you want to support me, you can offer me a coffee :

...if you like 🙂

Questions, feedback, or a new feature?

If you see a problem, have any remarks or questions, or would like to suggest a new feature, please contact me at antonin.info@protonmail.com.

Privacy & legal

This tool does not require an account and does not collect personal data such as names or email addresses. Your race settings and pacing calculations remain in your browser and are not stored on our servers. No third-party ads, no affiliate links, and no tracking cookies.

To improve the site, I use self-hosted analytics to understand which pages are used most. This data is stored on servers I control and is never shared with advertisers or third parties. The app is available worldwide. Depending on your location, local laws may grant you additional privacy rights. If you have questions about how data is handled, feel free to contact me.

This project is developed and maintained independently.

Translations are generated with the assistance of AI and may occasionally contain inaccuracies.

All results provided by this tool are estimates and should not be considered guarantees of race performance. Always listen to your body and follow appropriate medical advice.