Privacy policy

The short version: your cycle data never leaves your device. The longer version follows.

What we store — on your device only

Calculator inputs, logged period dates and your theme preference are kept in your browser's local storage so the site is convenient to reuse. This data exists only on your device. We cannot read it, and it is not transmitted to our servers, because our calculators perform no server-side processing of your inputs at all.

What we measure

We use aggregate, privacy-respecting analytics (page views, country-level region, device type) to understand which pages help people. These metrics contain no personal identifiers and no cycle data. We do not run third-party advertising trackers.

What we never do

We never sell or share personal data, never require an account, and never store health information server-side. If a feature ever needs more than on-device storage, it will ship off by default with explicit opt-in — and this page will say so.

How to delete everything

"Clear history" removes logged periods; "Start over" clears saved inputs; clearing your browser's site data removes both plus the theme preference. Because everything lives on your device, that is a complete deletion — nothing remains with us.

Advertising, cookies & EU consent

To keep these tools free, we plan to support this site with Google AdSense advertising. When ads are live, Google and its partners may use cookies and similar identifiers to serve and measure advertising, including based on visits to this and other websites. This page will always describe what is active, and visitors in the EEA and UK will see a consent choice before any ad-related cookie is set.

You can opt out of personalized advertising at any time via Google Ads Settings, and Google explains its data use in its "How Google uses information from sites or apps that use our services" page. We never pass the cycle data you enter into our calculators to any ad or analytics request.