6 Best Ovulation Calendar Apps for iPhone in 2025
I never thought I’d find myself deep in the world of ovulation tracker apps, but here we are.
A friend of mine was looking for the best ovulation calendar app for her iPhone, and as the go-to “iPhone app guy,” I decided to help her out.
After all, I run a blog dedicated to finding the best iPhone apps, so why not put my research skills to good use?
At first, I assumed all ovulation apps were the same—just basic period trackers with a calendar.
But after testing a bunch, I realized they’re surprisingly different.
Some focus on fertility and conception, while others prioritize hormonal balance, symptom tracking, or even birth control.
I also found that some apps overwhelm you with too much data, while others keep things refreshingly simple.
In this article, I’ll break down the best ovulation calendar apps for iPhone based on my research and testing.
Let’s dive in.
1. Clue – Best for Science-Backed Tracking
What worked for my friend:
- Backed by scientific research for accurate ovulation predictions
- Clean, intuitive design with no unnecessary clutter
- Tracks a wide range of symptoms beyond just periods and ovulation
- No overwhelming pregnancy-focused features—great for general cycle tracking
What didn’t work for my friend:
- Free version lacks advanced fertility insights
- Requires consistent data input for the best accuracy
Price: Free, $9.99 per month or $39.99 per year.
Get it from – App Store
I didn’t expect to be impressed by a period-tracking app, but Clue changed my mind.
While testing different ovulation calendar apps, I quickly realized that many of them were either overly complex or too focused on pregnancy.
But Clue? It strikes the perfect balance between science-backed accuracy and an easy-to-use design.
The first thing that stood out to me was how clean and modern the app feels.
No pink overload, no unnecessary baby-centric features—just a sleek and functional cycle tracker.
It tracks ovulation, periods, symptoms, moods, and even lifestyle factors like sleep and stress, which can all impact your cycle.
This makes Clue a solid choice not just for those trying to conceive but for anyone who wants to understand their body better.
What makes Clue truly shine is its accuracy.
Unlike some apps that make wild guesses, Clue’s predictions improve over time as you log more data.
It’s backed by science and even used in clinical research, which is a big deal in a space where many apps rely on basic calendar calculations.
That said, if you’re looking for deep fertility insights or personalized recommendations, you might need the Clue Plus subscription.
The free version is still great, but it doesn’t offer advanced ovulation analysis like some competitors.
Overall, Clue is my top pick for an ovulation calendar app on iPhone.
Whether you’re tracking your cycle for health reasons or planning for the future, this app does it all—without unnecessary distractions.
Similar guide: Best calendar apps for college students
2. Flo – Best for AI-Powered Predictions
What worked for my friend:
- AI-driven ovulation and period predictions improve over time
- Offers a private, anonymous community for discussions
- Doctor-reviewed health insights tailored to your cycle
- Beautiful, intuitive interface with easy data logging
What didn’t work for my friend:
- Free version limits access to advanced insights and features
- Some users may find the app too focused on fertility and pregnancy
Price: Free, $11.99 per month or $39.99 per year
Get it from – App Store
If there’s one app that almost everyone has heard of in the ovulation tracking space, it’s Flo.
With millions of users worldwide, I had to see what the hype was about—and I get it now.
Flo is like having a personal AI assistant for your reproductive health.
The app learns from your cycle data, using AI to predict ovulation and period windows with impressive accuracy.
The more you log, the smarter it gets, which makes it stand out from simple calendar-based trackers.
Plus, it offers doctor-reviewed insights based on your symptoms, so it’s not just about tracking—it’s about understanding your body better.
One thing I really liked is the app’s anonymous community feature.
If you have questions about fertility, cycle changes, or even general health concerns, you can ask them without revealing your identity.
It’s a surprisingly supportive space, and I can see why many users love it.
That said, Flo leans heavily toward pregnancy and fertility tracking, which may not appeal to everyone.
If you’re just looking for a simple ovulation calendar, some of the extra features might feel unnecessary.
Also, while the free version covers the basics, unlocking Flo’s full potential requires a premium subscription.
Still, if you want a smart, AI-driven ovulation tracker with a community aspect and expert-backed insights, Flo is one of the best options available.
Similar guide: Best ADHD calendar apps for iPhone
3. Ovia – A Completely Free App
What worked for my friend:
- 100% free with no paywalls or locked features
- Smart cycle predictions that improve over time
- Deep health tracking with insights tailored to individual data
- Tons of educational articles on fertility and reproductive health
What didn’t work for my friend:
- Some tracking features feel a little rigid with limited customization
- Cycle predictions weren’t always spot-on in the first month of use
Price: Free
Get it from – App Store
While testing different ovulation trackers for my friend, Ovia stood out for one major reason—it’s completely free.
No premium plans, no hidden features, just full access to everything.
That alone made it worth a closer look.
The more we tested it, the more we realized that Ovia is way more than just a basic cycle tracker.
It uses all the data you input—like symptoms, moods, and cycle history—to fine-tune its predictions.
Over time, it gets better at forecasting ovulation windows, which is great if you’re trying to conceive or just want to understand your cycle better.
One thing my friend really appreciated was the huge library of fertility-related articles built into the app.
Instead of Googling questions about symptoms or ovulation phases, she could just find answers right there.
It made learning about reproductive health feel more structured and less overwhelming.
That said, it’s not perfect.
While the tracking is solid, it’s not as customizable as apps like Clue.
And during the first month of use, the cycle predictions felt a little off, though they got more accurate over time as more data was added.
Still, for a free ovulation calendar app that offers smart tracking and personalized insights, Ovia is a fantastic choice.
If you don’t want to deal with subscriptions but still need a powerful fertility tracker, this is the one to try.
4. Natural Cycles – Best for Hormone-Free Birth Control
What worked for my friend:
- The only FDA-cleared birth control app that also tracks ovulation
- Uses basal body temperature (BBT) for precise cycle predictions
- Provides a hormone-free, natural alternative to birth control
- Great for both fertility tracking and preventing pregnancy
What didn’t work for my friend:
- Subscription-based with no free version available
- Takes time to adjust, best results come after 2-3 cycles
- You have to measure temperature consistently
Price: $16.99 per month or $119.99 per year.
Get it from – App Store
Natural Cycles is different from every other app on this list—it’s not just an ovulation tracker, but an FDA-cleared birth control method.
That immediately caught my attention because most apps focus solely on fertility and conception.
But this one? It helps with both planning and preventing pregnancy using a natural, hormone-free approach.
The app is designed for hormone-free contraception and claims to be 93% effective with typical use and 98% with perfect use—which is impressive for a natural birth control method.
It’s a great option for women who want to avoid hormonal contraceptives but still need a reliable way to track their fertility.
One thing I really liked is how it adapts to irregular cycles.
Most period trackers assume a standard 28-day cycle, but Natural Cycles learns your unique pattern over time.
My friend found that after a couple of months of tracking, the app started giving incredibly accurate predictions about her ovulation and fertility windows.
The app also offers flexible tracking options.
You can either measure your temperature manually with the NC° Thermometer (which comes free with an annual subscription), or you can sync it with an Apple Watch (Series 8 or newer) or an Oura Ring.
This makes tracking way easier, especially if you don’t want to take your temperature first thing every morning.
However, it’s not free.
A subscription costs $16.99 per month or $119.99 per year, which might not be ideal for everyone.
That said, if you’re looking for a scientifically-backed, hormone-free way to track fertility, Natural Cycles is one of the best options available.
Just be prepared to commit to regular temperature tracking for the best results.
5. Premom – Best for At-Home Ovulation Testing
What worked for my friend:
- Syncs with ovulation test strips for precise fertility tracking
- AI-powered ovulation predictions based on hormone levels
- Offers free fertility courses and expert guidance
- Allows tracking of basal body temperature (BBT) and cervical mucus
What didn’t work for my friend:
- Works best when paired with ovulation test kits
- Interface can feel cluttered with too much data at times
Price: Free or $20.49
Get it from – App Store
Premom takes ovulation tracking to the next level by integrating at-home ovulation test strips with its app.
While most apps rely on calendar-based tracking, Premom goes deeper by using actual hormone levels to predict fertility windows more accurately.
If you’re serious about tracking ovulation—whether for conception or just better cycle awareness—this app is a strong contender.
What sets Premom apart is its ability to scan and interpret ovulation test strips directly in the app.
If you’ve ever used LH (luteinizing hormone) test strips, you know how tricky they can be to read.
Premom eliminates the guesswork by using AI to analyze test results and predict ovulation with greater precision.
It also tracks basal body temperature (BBT) and cervical mucus, giving you multiple ways to confirm ovulation.
Another highlight is the free fertility courses and expert guidance offered within the app.
Unlike some apps that just track data, Premom actively educates users on how to optimize their fertility tracking.
It even provides personalized recommendations based on your unique cycle trends.
However, this app works best when paired with ovulation test strips, so if you’re not planning to use them, you might not get as much value from it.
Also, the interface can feel overwhelming with the sheer amount of data it provides.
That said, if you’re looking for an ovulation calendar app that goes beyond basic tracking and incorporates real hormone data, Premom is one of the most advanced options available for iPhone users.
6. Period Tracker by GP Apps – A Simple and Private Tracker
What worked for my friend:
- Super simple—no learning curve at all
- Lets you log symptoms, moods, and weight effortlessly
- The app icon is discreet, labeled as “P Tracker” for privacy
- Syncs with Apple Health for better tracking
- Handy reminders for periods and ovulation
What didn’t work for my friend:
- Lacks advanced fertility tracking features
- Not the best option if you have irregular periods
- The interface feels a little outdated compared to newer apps
Price: Free or $9.99 per year
Get it from – App Store
This was one of the first period tracking apps I ever checked out, and honestly, I see why so many people still use it.
It’s ridiculously easy—just open the app, log your period, and it predicts your next cycle and ovulation days.
One thing my friend really liked was how discreet it is.
The app icon just says “P Tracker,” so no one would immediately guess it’s a period tracker.
The interface itself is also super beginner-friendly—just log your period dates, and the app does the rest, predicting your next cycle and ovulation window without needing any extra input.
It also lets you log symptoms, moods, and even weight changes, which was useful for my friend to notice patterns over time.
And since it syncs with Apple Health, all the cycle data stays in one place along with other health stats.
The biggest downside?
It’s pretty basic compared to apps like Clue or Flo.
There’s no AI-driven insights, no deep fertility tracking, and the design feels a bit outdated—functional, but not as polished as some of the newer apps.
That said, if you just need a simple, private, and easy-to-use period tracker, this one does the job perfectly.
My friend liked that it wasn’t overwhelming and didn’t require extra effort to use.
If you want deep fertility insights, you’ll need something more advanced—but for casual tracking, this app works great.
My Final Take
After testing all these apps to help my friend find the best ovulation tracker, I realized there’s no single perfect choice—each app shines in different ways.
- If you want a simple, reliable tracker, Flo is the easiest and most user-friendly option.
- If you’re trying to conceive, Ovia goes deep with cycle insights and personalized tips.
- If you want a hormone-free birth control option, Natural Cycles is FDA-cleared but requires commitment.
- If you need the most precise ovulation tracking, Premom is unbeatable when paired with test strips.
So, which one should you download?
Honestly, if I were in my friend’s place, I’d use at least two.
She found Flo perfect for everyday tracking, but Ovia’s insights gave her a better understanding of her cycle.
If she ever wanted a natural birth control option, Natural Cycles would be worth considering.
At the end of the day, it’s all about what works best for you.
FAQs
Can I rely solely on ovulation calendar apps for contraception?
While ovulation calendar apps can help track your menstrual cycle and fertile windows, they should not be solely relied upon for contraception. Experts warn that the accuracy of these apps varies, and using them as the only method of birth control can increase the risk of unintended pregnancies.
How accurate are ovulation calendar apps in predicting fertile days?
The accuracy of ovulation calendar apps depends on various factors, including the quality of data input and the specific algorithms used by the app. Some apps, like Clue, are recognized for their scientific approach and accuracy. However, it’s essential to remember that individual cycles can vary, and no app can guarantee 100% accuracy.
Are there any free ovulation calendar apps available for iPhone?
Yes. Ovia is completely free with full access to ovulation tracking and insights, making it the best no-cost option for iPhone users.
Can ovulation calendar apps help if I have irregular periods?
Yes, certain apps are designed to assist users with irregular periods. For instance, Flo is recognized for its effectiveness in tracking irregular cycles and providing personalized insights. However, it’s advisable to consult with a healthcare professional for personalized guidance if you have irregular periods.
Do ovulation calendar apps offer community support or educational resources?
Many ovulation calendar apps provide community support and educational resources. For example, Glow offers access to a large online community and health resources to support users along their fertility journey.
Can I use ovulation calendar apps to plan activities around my menstrual cycle?
Yes, menstrual apps like Flo, Period Tracker, and Clue enable users to track their cycles and predict stages, helping plan activities around times when they might experience premenstrual symptoms or feel more energetic.
Is my personal data safe with ovulation calendar apps?
Data privacy policies vary between apps. It’s essential to review the app’s privacy policy to understand how your data will be used and protected. Choosing apps with robust security measures can help ensure your personal information remains confidential.
Can ovulation calendar apps sync with other health apps or devices?
Many ovulation calendar apps can sync with other health apps or devices. For example, Period Tracker by GP Apps offers integration with Apple’s Health app, allowing for a more comprehensive health tracking experience.
