The tilde means estimated.
You can tell at a glance when the day is approximate.
Free private cycle tracker for partners
Understand her cycle.Show up better.
Cycles helps men and partners understand the menstrual cycle without claiming certainty. Log an exact date—or simply “on her period now” or “PMS signs”—and get a clear best guess with its confidence left visible.
Free for early usersNo subscription
- No account
- On-device only
- Private by design
Lea’s cycleDrag to explore
Medium confidence±3 days
Based on premenstrual signs noted 11 days ago.
You probably do not know every date.
That is the point.Cycles works with honest signals instead of asking you to invent precision.Works with what you know
You do not need the exact date to begin.
Pick the information you actually have. Cycles decides how much to trust it and says so plainly.
What Cycles does
A useful range, not a made-up date.
Cycles places the likely start within the period window, then keeps the uncertainty visible.
Medium confidence±2 days
Confidence fades honestly as information gets older
Honest uncertainty
A best guess should look like one.
Cycles never hides the difference between an exact date and an estimate. Three small signals keep the uncertainty readable.
The range stays visible.
Soft signals and irregular cycles widen the window.
The basis is written out.
No mystery score—just the information behind the guess.
The cycle, in context
Four phases. Written for the person paying attention.
The app personalizes the ranges. This 28-day example shows the kind of support that may land well.
Menstrual
Days 1–5Energy is often at its lowest—cramps and fatigue are common.
Low-key plans and warmth go a long way.Follicular
Days ~6–11Energy, mood, and focus often climb day by day.
The best stretch for plans and new things.Ovulation window
Days ~12–15Energy and confidence often peak around these days.
Shown as an estimate, never contraception advice.Luteal
Days ~16–28The final days can bring PMS—mood dips, cravings, tiredness.
Don’t take it personally. Patience and snacks.Every body is different—Cycles learns each person’s real rhythm from whatever you log.
Yours alone
The data stays with you.
Cycle information is sensitive, so Cycles keeps the architecture deliberately small: one iPhone, no account, no analytics.
No account or cloud
Profile and cycle data stays in local app storage.
Optional Face ID
Lock the app when it returns from the background.
Deliberate export
Create a portable copy only when you choose.
Real deletion
Remove one profile or wipe everything from the device.
On-device onlyNo Cycles account
Questions, answered
The clear version.
If the app is making a guess, it should be direct about how and why.
Cycles is a private cycle tracker for partners who want useful context without pretending an estimate is certain. It is especially helpful for men who want to understand menstrual phases, communicate better, and remember information a partner has chosen to share.
Only with their knowledge and consent. Cycles is designed for shared awareness and support, not surveillance. Log only information your partner has chosen to share, and delete a profile whenever that consent changes.
You can log that her period is happening now, note PMS or premenstrual signs, or add a plain note. Cycles weighs each signal differently and shows how uncertain the resulting estimate is.
That depends on what has been logged, how recent it is, and how regular the real cycle is. An exact period start produces a tighter estimate; softer or older information produces a wider range. Cycles shows its confidence and basis instead of presenting every date as exact.
Cycles provides educational cycle context and estimates. It is not a medical device, diagnostic tool, fertility treatment, or contraception method, and its predictions should never be used to decide when unprotected sex is safe.
Profile and cycle data stays on your iPhone. Cycles has no account, cloud sync, or analytics. You can optionally use Face ID, export a copy, or delete everything from the device.
Cycles is free for early users, with no subscription. If a one-time price is introduced for new downloads later, people who already received Cycles for free will keep it free.
Cycles is available on the App Store for iPhone. Use any App Store button on this page to open the listing.
Available for iPhone
Stay tuned in, without pretending to know everything.
Cycles is free for early users, with no subscription. If a one-time price is introduced for new downloads later, early users keep it free.
Free for early users · No subscription · iPhone