How accurate is Flo?
You can keep your predictions as accurate as possible by consistently tracking your cycle and symptoms and editing any past cycles where you didn't log accurately.
Using Flo you can better your understanding of when your period may start, when you may be ovulating and when your fertile window may be.
The more you log your cycle dates, the more accurate our predictions for you will be. We call it teamwork!
90%
of users said Flo accurately predicts the start of their period.1
#1 app
for period and cycle tracking recommended by OB-GYNs.4
Why is Flo so accurate?
Every time you log your period dates, your Flo becomes more accurate. The app uses these to provide you with unique cycle predictions and knowledge — helping you understand your body better. If the Flo algorithm can’t accurately predict cycle length, especially if you experience irregular cycles or don’t use the app regularly, the app widens your fertile window to around 14 days.
With Flo’s help, you can learn more about:
Your cycle length
When you log your period dates, Flo can predict your current cycle length. You can also sync temperature data from wearable devices like smartwatches and rings (or manually add it). Temperature can change slightly at key points in your cycle, so this information helps make Flo’s predictions more accurate. Learn more about tracking your cycle with Flo.
When you might ovulate
It’s impossible to predict ovulation with 100% accuracy (it can change monthly, after all and lifestyle factors like stress can impact it). But, when you log your cycle dates, your Flo app can help you understand some of the signs that could indicate when you’re most fertile during your cycle. Remember, Flo’s predictions should not be used as a method of birth control or to facilitate conception. Find out more about getting pregnant with Flo.
Your approximate pregnancy due date
Like your doctor, the Flo app calculates your due date by adding 40 weeks to the first day of your last period (around 280 days). That’s why it’s so important to correctly log your period dates when you’re trying to get pregnant. But, if you miss a month or two, don’t stress — you can manually add your due date, too. Learn more about tracking your pregnancy with Flo.
Your cycle length
When you log your period dates, Flo can predict your current cycle length. You can also sync temperature data from wearable devices like smartwatches and rings (or manually add it). Temperature can change slightly at key points in your cycle, so this information helps make Flo’s predictions more accurate. Learn more about tracking your cycle with Flo.
When you might ovulate
It’s impossible to predict ovulation with 100% accuracy (it can change monthly, after all and lifestyle factors like stress can impact it). But, when you log your cycle dates, your Flo app can help you understand some of the signs that could indicate when you’re most fertile during your cycle. Remember, Flo’s predictions should not be used as a method of birth control or to facilitate conception. Find out more about getting pregnant with Flo.
Your approximate pregnancy due date
Like your doctor, the Flo app calculates your due date by adding 40 weeks to the first day of your last period (around 280 days). That’s why it’s so important to correctly log your period dates when you’re trying to get pregnant. But, if you miss a month or two, don’t stress — you can manually add your due date, too. Learn more about tracking your pregnancy with Flo.
Frequently asked questions
Medical accuracy underpins everything we do at Flo. Here’s how we make sure all of our stories, articles, and insights are medically backed up:
- Our team of 120+ doctors and health experts reviews all of the content — and tools — we create to ensure the information we provide you with is up to date, accurate, and trustworthy.
- Our team of 20 research scientists commissions studies and research to address the gaps in what doctors know about female health.
All of our articles, videos, and courses are created in line with our editorial standards.
Download the app, choose your goal (tracking your cycle, trying to get pregnant, or tracking your pregnancy), and start logging! You can start using Flo without adding any information about your previous cycles. However, our predictions will be more accurate if you log the dates of at least three previous periods. You can also manually add your pregnancy due date.
References
- AppFollow, Apr'24, iOS
- Sensor Tower, August 2023, by downloads
- Total app downloads
- Survey of 500 US OB-GYNs, DRG (2021)
- Monthly active users as of May ’24
Understand what your symptoms might mean — and what's normal for you — by tracking your cycle.
Follow your baby's growth and see how your body is changing.
Know when you're most fertile to maximize your chances of getting pregnant.
