Privacy Policy

Basic usage analytics

Aggregated metrics such as page views and general device/browser type to understand overall usage. We do not store precise locations or behavioral profiles.

Cookies and local storage

Essential cookies or local storage keep preferences like units and language working. Analytics tools may set their own cookies.

Email you send us

If you email support@marathoncalc.com, we receive your email address and the content you provide so we can reply. We do not run contact forms or invisible trackers.

Operate, maintain, and improve

Operate, maintain, and improve the site and its JSON tools.

Diagnose and protect

Diagnose performance or availability issues and protect against abuse.

Respond to support

Respond to support requests and feedback you send by email.

3-1. Legal Basis for Processing (EEA / UK)

For users located in the European Economic Area (EEA) and the United Kingdom, we process personal data based on one or more of the following legal grounds, as applicable: Your consent, where required for cookies and advertising technologies. Legitimate interests, such as maintaining site security and improving our services. Compliance with legal obligations.

Advertising

We use Google AdSense to serve advertisements. Google's use of advertising cookies enables it and its partners to serve ads to our users based on their visit to this site and/or other sites on the Internet.

Opt-out

You may opt out of personalized advertising by visiting Google Ads Settings or www.aboutads.info.

Hosting & Security

We use Vercel and Cloudflare to ensure high performance and safety.

Limit analytics

Privacy-focused browsers or blockers can restrict analytics scripts. Core calculator features work without them.

Control cookies

You can clear cookies or local storage. Preferences like language or units may reset afterward.

Manage emails

You can request deletion of prior emails by writing to support@marathoncalc.com. Once removed, we will not retain your message history.

How long we keep data

Aggregated analytics are kept for trend analysis. Support emails are retained only while needed to respond and track recurring issues.

Protective measures

We avoid collecting unnecessary personal data, use HTTPS, and limit access to operational tooling.

Children

This service is not directed to children under 13. If you are a guardian and believe a child has contacted us, please email us.

Policy changes

If this policy changes, we will update the date above and publish the revised version on marathoncalc.com.

Questions

Contact support@marathoncalc.com with any privacy questions or requests.