Your cycle, simplified.
Log your period in a couple of taps. Plum learns your cycle and tells you what to expect next.
A little log goes a long way
Log in a tap
Tap yes, pick a flow, done. Plum fills in the rest of your period automatically.
Predictions that learn
Period, fertile window, and ovulation forecasts get sharper with every cycle you log.
Tips for the phase you're in
Practical suggestions matched to where you are in your cycle.
Share your cycle with the people closest to you.
Send a private link, and your closest friends can see where each of you is in the month. You choose which groups see your cycle, and you can change it any time. Free for everyone.
Your cycle is yours.
Health data is personal. Plum is built so it stays that way.
Read up on your cycle
Longer answers on cycle length, the fertile window, irregular periods, and how to pick a private tracker, with sources linked throughout.
How long is a normal menstrual cycle?
Average cycle length, the normal range for adults and teens, what makes cycles vary, and the changes that mean it is time to talk to a clinician.
Read the guideWhat is the fertile window and how is it calculated?
The fertile window is the handful of days each cycle when pregnancy is possible. How apps and clinicians estimate it, and where estimates fall short.
Read the guideIrregular periods: common causes and when to see a doctor
From stress and travel to PCOS and thyroid problems, the common reasons periods go irregular, and the symptoms that deserve a visit to a clinician.
Read the guideHow to choose a period tracker that respects your privacy
Period apps hold some of your most sensitive data. A practical checklist for judging a tracker’s privacy by what its policy actually says.
Read the guideThe things people ask us
Is Plum free?
Yes. Logging, the calendar, predictions, reminders, and shared groups are all free, with no ads. Plum Premium adds deeper insights and phase tips for $37.99 a year, after 7 days free, or $8.99 a month with no trial. Those are US prices; the App Store shows your local price before you buy.
Is Plum available on Android?
Not yet. Plum is on iPhone today. An Android version is something we would like to build, and the best way to hear about it is to write to us so we can tell you when it lands.
Can Plum be used as birth control?
No. Plum predicts your fertile window from the cycles you log, but predictions are estimates and cycles vary. Plum is a wellness app, not a medical device or a contraceptive, and it should not be used to prevent or achieve pregnancy.
Who can see what I log?
Only you, unless you choose otherwise. Your data is encrypted in transit and at rest, it is never sold and never used for advertising, and if you join a group you decide per group whether to share, and members see only your last period, your next expected one, and your current phase. Never your notes or symptoms.
How accurate are the predictions?
They sharpen with every cycle you log. Plum starts with a typical cycle length, then adapts to your own average and how much it varies, and it tells you when it is still learning rather than pretending to be certain.
How do I cancel Premium?
In your iPhone Settings, under your name, then Subscriptions. Cancelling there stops the renewal and you keep Premium until the period you already paid for runs out. Deleting the app does not cancel a subscription.
Still stuck? We answer every email.