buncha/health & fitness/period

Period Tracker

Your data stays on this device. Periods are saved to this browser's local storage only — no account, no upload, no analytics on the entries themselves. Export a CSV any time to take it with you, or clear everything in one click.

Start by logging your last period. Pick the start date and approximate duration. After 2+ entries we can start predicting cycle length and your next period.

Log a period

Start date

Duration (days)

Flow (optional)

Notes (optional)

This is a tracker, not a diagnostic tool. Cycle predictions are based on averages of your logged data and textbook luteal-phase length (~14 days before the next period). Real cycles vary widely. If predictions feel off, log more cycles — accuracy improves with data. For pregnancy planning, contraception decisions, or any concerning symptoms, talk to a clinician.

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About Period Tracker

Log periods month-over-month. Cycle history, average length, next-period prediction, current phase. Stays on your device.

Everything happens on your device. Close the tab and it's gone.