Apple Watch Series 8 Includes Ovulation Tracking

Woman laying in a bed wearing a watch and holding a phone

Oleksandra Troian / Getty Images

Key Takeaways

  • Apple’s new Series 8 watch comes with a highly sensitive temperature sensor that may help track ovulation.
  • The technology is based on the fact that your temperature rises slightly after you ovulate, so tracking your temperature can help you understand your fertility patterns.
  • Besides temperature shifts, ovulation can be predicted by tracking cervical fluid changes, using an ovulation predictor kit, and tracking these changes together on a smartphone app.

If you are trying to conceive, or simply looking for new ways of tracking your cycle, the newest Apple watch has some features that might be of interest to you. Apple’s redesigned Series 8 watch has updated, highly sensitive temperature sensors that Apple claims will be able to help users know when they’ve ovulated.

Tracking ovulation is a powerful tool for people trying to get pregnant. But understanding the ins and outs of ovulation tracking can get confusing!

Can My Apple Watch Tell Me When I'm Ovulating?

According to the company, the new Apple Series 8 watch (along with the redesigned Apple Watch SE) has a few features that focus on reproductive health. The most prominent feature is the watch’s temperature sensor. There's one sensor directly touching your skin and another found under the display of the watch. This “two-sensor” design is meant to increase accuracy, by reducing bias from the external environment.

The company suggests wearing the watch overnight, and your temperature is taken every 5 seconds. As Apple describes, the watch is able to sense temperature changes as minor as 0.1° C. From there, your Apple watch will track your temperature shifts and patterns in the Health app of your watch using what Apple refers to as “retrospective ovulation estimates.”

Photo of Apple watch showing ovulation estimate as well as an iPhone


Apple’s temperature tracking is based on the fact your temperature rises once ovulation is complete (called basal body temperature, or BBT). This shift can be tracked using highly sensitive thermometers and must be tracked when the body is at rest. Using the temperature method to track ovulation only verifies ovulation after it happens. This is what is meant by a retrospective estimate of ovulation.  

Apple notes not only can these new features help you predict when you will ovulate, but they can help you understand if there are irregularities in your cycle or signs of other health conditions.

How Do Ovulation Trackers Help You Get Pregnant?

Tracking your basal body temperature is just one of several pieces of data that may be used by an ovulation tracker. Ovulation trackers also collect information about changes in your cervical fluid around the time of ovulation or test results from an ovulation predictor test, explains Susan Lipinski, MD, an OB/GYN at Obstetrix of Colorado, part of Pediatrix Medical Group.

What an ovulation tracker does is take all of this data and put it together to help you gain a better understanding of your body’s patterns when it comes to ovulation, explains Dr. Lipinski. Often, it takes a few cycles of data collection for your tracker to see a pattern and help you predict when your ovulation window might be. An ovulation tracker can be an app you use on a phone, a computer program, or even a chart kept by hand.

Once you have tracked these signs for a while, you will be able to understand what it looks like when you are ovulating and then you can time intercourse around this. You are most fertile during the day or two before and the day after ovulation, Dr. Lipinski explains.

“Sperm can live for five days but once released, the egg can only survive 24-48 hours unless it is fertilized,” she describes. “For those wishing to conceive or to avoid pregnancy, ovulation tracking is an excellent way to do so.”

Aumatma Simmons, ND

Knowing when you are ovulating is crucial to determine the right time frame for sex so that pregnancy can happen.

— Aumatma Simmons, ND

Aumatma Simmons, ND, board certified in Naturopathic Endocrinology, and a fertility expert with 15 years of experience, agrees. “Knowing when you are ovulating is crucial to determine the right time frame for sex so that pregnancy can happen,” explains Simmons, known as “Dr. Aumatma.” Most of us are never taught about ovulation, or how to recognize and track the signs, Dr. Aumatma says, and this is why ovulation trackers can be so helpful to couples trying to conceive.

How Accurate are Ovulation Trackers?

The accuracy of an ovulation tracker really depends on the type of data it's tracking, explains Dr. Aumatma. “Unfortunately, not all ovulation trackers are made equal,” she says. Some trackers simply calculate your fertile window based on your previous menstrual cycle or your cycle history. A more accurate ovulation tracker would rely on more than one method to predict or confirm ovulation, she says.

Another point to keep in mind, says Dr. Aumatma, is what type of tracker to use really depends on each individual person and their needs. “There are no generalizations,” she says. When you are considering which type of tracker or which data to track, you should discuss this with your healthcare provider, she adds.

Adi Davidov, MD, associate chair of obstetrics and gynecology at Staten Island University Hospital, part of Northwell Health in New York, says of the different methods out there to monitor ovulation, ovulation predictor kids are usually the most accurate. Ovulation predictor kits, which are available over-the-counter in most pharmacies, use a urine sample to detect a surge in the luteinizing hormone (LH), which is released about 36 hours before you ovulate, says Dr. Davidov.

“Ovulation prediction kits are about 90 to 95% reliable,” Dr. Davidov notes. “They may occasionally have false positive results—especially if a patient has conditions that may increase the LH levels such as polycystic ovarian syndrome, ovarian insufficiency, and perimenopause.”

Susan Lipinski, MD

The wearable BBT trackers are helpful because they measure at the same time without the need to remember.

— Susan Lipinski, MD

Dr. Lipinski says that tracking your basal body temperature is a good method to detect ovulation, but it can be difficult to do so consistently. “It is necessary to measure at the same time every morning before getting out of bed or drinking/eating anything,” she describes. She sees promise in a wearable device that measures body temperature at the same time each day.

“The wearable BBT trackers are helpful because they measure at the same time without the need to remember,” Dr. Lipinski says. “Of course, many things can also alter basal body temperature such as illness or medications, so this is not a perfect way to track.”

What's the Difference Between Ovulation and Period Trackers?

If you are confused about the difference between an ovulation tracker and a period tracker, you are not alone. The main difference is that period trackers focus on the calendar—when your period last came, and how many days elapsed between one cycle to another. On the other hand, ovulation trackers look at body signs such as temperature changes, cervical fluid changes, and data from ovulation predictor tests.

When it comes to predicting ovulation, period trackers alone are usually not sufficient, as Dr. Aumatma explains. That’s because period trackers guess ovulation based on textbook definitions of when people ovulate. For example, many period trackers will predict that you’ll ovulate 14 days after your period starts, but this is just an average. Every person is different—and may have different ovulation dates from one month to the next.

“In reality, this same [person] who has a ‘regular cycle’ may be ovulating before or after this predicted window, and may not be conceiving solely because of the inaccurate prediction from this tracker,” Dr. Aumatma explains.

What. This Means For You

Trying to conceive can be hard enough at times, and having a little assistance from an ovulation tracker can be immensely helpful. That said, not all trackers are equally helpful, and no tracker is a substitution for specialized care from a healthcare provider. If you have any concerns about your pregnancy journey, or any further questions about tracking your fertility, please reach out to your doctor or midwife.

5 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Apple Inc. Apple reveals Apple Watch Series 8 and the new Apple Watch SE.

  2. Mayo Clinic. Basal body temperature for natural family planning.

  3. Su H, Yi Y, Wei T, et al. Detection of ovulation, a review of currently available methods. Bioengineering and Translational Medicine. 2017;2(3):238-246. doi:10.1002/btm2.10058

  4. Su H, Yi Y, Wei T, et al. Detection of ovulation, a review of currently available methods. Bioengineering and Translational Medicine. 2017;2(3):238-246. doi:10.1002/btm2.10058

  5. Vigil P, Lyon C, Flores B, Rioseco H, Serrano F. Ovulation, a sign of healthLinacre Q. 2017;84(4):343-355. doi:10.1080/00243639.2017.1394053

By Wendy Wisner
Wendy Wisner is a lactation consultant and writer covering maternal/child health, parenting, general health and wellness, and mental health. She has worked with breastfeeding parents for over a decade, and is a mom to two boys.