The Nourished Blog

Apple Watch Series 8 vs. Oura Ring: Tracking Basal Body Temperature for Natural Birth Control

Many women who are looking for natural birth control (aka the Fertility Awareness Method) are curious about the rise in popularity of wearable body thermometers to track their basal body temperature.

With a variety of temperature tracking devices out there, it poses the question: How do these new technologies compare in both ease and accuracy?

These are important questions to ask when choosing a thermometer for natural birth control accuracy!

Recently, there have been two big advancements in wearable body thermometers for natural birth control:

  1. The collaboration between Oura Ring and Natural Cycles 
  2. The Apple Watch series 8’s newly integrated fertility features 

So here is the big question… 

Are these devices a good option when tracking your basal body temperature for birth control accuracy?

First, it’s important to understand why we track basal body temperature (BBT) for Fertility Awareness Method in the first place.

I want to be very clear here… BBT does NOT predict when ovulation is going to occur.

This is a huge misconception.

BBT can only confirm AFTER ovulation has passed.

This is due to the slight increase in body temperature (.4-.5 degrees) caused by the hormone progesterone post-ovulation. If you want more of a deep dive into basal body temperature for birth control, you can read my blog post here.

Now, let’s dig into these new technologies and my thoughts on utilizing them for natural birth control.

The collaboration between OURA Ring and Natural Cycles for tracking basal body temperature

The Oura Ring is a wearable thermometer that you wear on your finger. They have recently teamed up with Natural Cycles (NC), which is the first FDA-cleared birth control app.

Natural Cycles normally utilizes an oral basal body temperature device (manually taking your temp in the morning) and their algorithm uses this data to predict your fertile and infertile days.

With NCs new collaborations with Oura Ring, you can now opt to use the ring, which will track your temperature overnight. NC’s algorithm analyzes trend data from the Oura Ring and then translates this temperature in the NC app to determine your fertile window.

I think it is important to note that the Oura Ring does not measure your actual temperature. Rather, “it measures how much your body temperature from your most recent night’s sleep has changed, either in a positive or negative direction, from your long-term average.” In addition, Oura measures your skin temperature, which is not the same as core basal body temperature.

In my mind, this could cause some variation and inaccuracy when using these temperatures for natural birth control purposes – but I do know this is where the Natural Cycles algorithm comes in.

Essentially, when using this method, you’re looking for big picture “trends” to determine which phase of the cycle you are in. You are also using NC’s algorithm, and past cycle data, to give you a prediction of your fertile and infertile days.

If we go back to remembering that BBT only confirms AFTER ovulation has happened, you can see that you’re putting a lot of trust in your “trends” and an algorithm to predict your daily fertility.

Do I think this means the Natural Cycles and Oura Ring collaboration is not a good natural birth control option?

Not necessarily.

But, I want people to understand that this is definitely not using Fertility Awareness Method.

I think you can use the Oura Ring and Natural Cycles for birth control (if you want), but I 100% believe you need to have a strong understanding of cervical mucus because this is your only TRUE (in real time) data of whether or not you’re fertile or infertile.

Remember, basal body temperature only confirms after your fertile window has passed. So there is some margin of error when you’re relying on technology to use past data and an algorithm to determine your fertility.

With Fertility Awareness Method, there are special protocols in place around cervical mucus, BBT, and peak day “rules” that gives you that 99% birth control accuracy. The POWER of Fertility Awareness Method is understanding how to interpret your own fertility , and how to chart them accurately for natural birth control. YOU are in control, not the technology.

In addition, the cost of purchasing the ring, plus the ring subscription, and the NC subscription is quite an expensive way to use natural birth control. Especially when you consider you’re putting all your trust in temperature trends and an algorithm. But, whatever makes you feel the most comfortable is the best choice for you!

The Apple Watch Series 8’s New Integrated Fertility Features 

Reading more about this new fertility tracking update with the Apple Watch has been super interesting! 

The Apple Watch Series 8 samples wrist temperature during sleep every five seconds at night and it is capable of measuring changes as small as 0.1-degrees Celsius in the body. This is incredibly sensitive!

After doing some research, I love that the Apple Watch Series 8 is not claiming to “predict your fertile window” and instead is using retrospective temping data that can that suggest you may have ovulated (after the fact!) which is exactly how we use temperature tracking with Fertility Awareness Method.

The Apple Watch is also not suggesting that this new feature should be used for natural birth control and that you can only utilize the data to help make helpful conclusions about your cycle. Therefore, you are simply utilizing the BBT feature from the watch, but you still need to apply the rules of Fertility Awareness Method to determine if your fertile window is open or closed.

Essentially, it’s just like using any accurate temperature tracking device for natural birth control – you still need a “method” to understand how to interpret your data for contraceptive purposes. I’m down with this!

I want to say that I do not think you NEED an Apple Watch to track your basal body temperature for natural birth control. This would be an incredibly expensive wearable thermometer to purchase. But if you already have one, and are using it for other purposes, you can totally utilize the new and more sensitive basal body temperature sensor.


This is very similar to the way I teach clients to use the wearable body thermometer Tempdrop.

Tempdrop is specially designed to track your most accurate resting temperature overnight and uses a special algorithm to factor out any disturbances.

In my mind, the difference here is that Tempdrop is designed to track your most accurate basal body temperature by eliminating the inconsistencies of sickness, environmental factors, disrupted sleep, etc. (Note that this algorithm isn’t predicting your fertile window; instead, it is factoring out any sleep disturbances for an accurate reading.)

The Apple Watch Series 8 (to my understanding) isn’t going to use a special algorithm to make sure you’re getting the most accurate reading if there are other factors at play that may cause temperatures to be inconsistent. This is the power of Tempdrop, truly!

In general, the perk of a wearable thermometer is that you don’t have to worry about waking up at the same time every day to take your oral temperature. This can definitely make tracking basal body temperature for fertility awareness methods much simpler.

EMF Exposure

The other perk of Tempdrop is the fact that you do not have to worry about EMFs, which is incredible when you’re wearing a device overnight. Tempdrop only releases EMFs when you’re actively syncing it to your phone, which you can do the morning after, or even every few days.

On the other hand, the Apple Watch emits quite a lot of EMFs. This is from the EMF Academy: “The Apple Watch is one of the most connected devices you can put on your wrist, as it connects via Bluetooth, WiFi, and cellular. One of the major dangers with wearable tech like the Apple Watch is that it is constantly in direct contact with your skin.”

The Oura Ring is much more minimal when it comes to EMF exposure. Their website states: “The Oura Ring emits minimal electric and magnetic fields (EMFs) and allows you to enable Airplane Mode to limit contact even further.”

Final Conclusions on Wearable Body Thermometers for Natural Birth Control

If you’re interested in tracking your basal body temperature and using Fertility Awareness Method, my advice would be to go the cheapest and most highly effective route. 

In my opinion, this is why I recommend Tempdrop as my go-to wearable thermometer for natural birth control.

Not only does its algorithm give you the most accurate information, but you are in charge of using that information to determine your fertile window. In addition, you will be using cervical mucus clues to open and close the fertile window – not just temperature.

The other amazing perk of using Tempdrop is that it syncs to my favorite FAM application – Read Your Body. With both of these tools together, you can accurately follow the rules and protocols of Fertility Awareness and use the method effectively for natural birth control.

I think that you can totally use the Apple Watch Series 8 and the new sensor for tracking BBT, although this is quite an expensive option. Unless you’re using the Apple Watch for other purposes.

It may not be quite as accurate as Tempdrop (due to Tempdrop’s algorithm for weeding out sleep disruptions), but it will totally work. You will also need to manually input these temperatures into your preferred FAM charting method – I recommend Read Your Body.

While I am not totally against the Oura Ring and Natural Cycles collaboration, I want to be clear that it is not the same thing as learning Fertility Awareness Method. 

Instead, you’re utilizing the convenience of technology and relying on predictions, algorithms, and trends to determine when your fertile window is open or closed. You’re most likely not considering cervical mucus observations, as the technology does not factor this into its decision. This is where mistakes can happen. It is also quite an expensive option.

I am all here for technology and women having OPTIONS when it comes to natural birth control.

You really need to pick the devices and methods that work best for you and your lifestyle.

My top vote will always be Tempdrop + Read Your Body, but I hope that this blog post helps you determine what resources will work best for you!

If you want to learn more about how to ditch birth control and prevent pregnancy naturally with Fertility Awareness Method, you can register for my free class here!

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Hi, I’m Nina! I’m a Certified Fertility Awareness Educator who teaches women how to transition off of birth control and prevent pregnancy hormone-free.

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