Which basal body temperature thermometer to get

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My favourite Basal Body Temperature thermometers

So you are ready to start charting but as you tell your fertility savvy friend that you’ll just use the thermometer in your medicine cabinet, she looks at you with horror. Of cooourse you should not be using that old thing, you need a “BBT” thermometer. You laugh, hide your confusion, and say “I was just kidding silly”. As soon as she hits the bathroom you grab your phone and search “BBT thermometer” and you find this post.. I’m with you girl! You’ll know what to get before she’s back!

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What is a BBT thermometer?

Ok, just quickly. BBT stands for Basal Body Temperature. If a thermometer is a BBT thermometer, it just means that it is more sensitive than regular thermometers because you want to be able to pick up on the subtle temperature changes throughout your cycle. A BBT thermometer will measure to a two decimal point (eg 98.00° F or 37.00° C ). Good, so now you can throw that term around like your friend and you are up to speed when she returns!

What thermometer to get? Well, it needs to check two boxes as far as I’m concerned when you start with charting:

1. It needs to have 2 decimal places (Fahrenheit or Celcius)

2. It needs to be CHEAP. That way you’ll likely not over-think the purchase and get started charting as soon as possible.

If you have already tried the cheap type or want to spend more time to choosing a BBT thermometer, you can consider what most of my patients and myself have found to be practical:

  • The option to choose between Fahrenheit or Celcius
  • A thermometer that remembers more than 1 reading
  • A back light for if you want to record the temperature in the early dark
  • A thermometer that syncs automatically with your phone
  • A thermometer that buzzes instead of beeps when it’s ready so it doesn’t wake hubby or co-sleeping babies

Now that you know what options to consider, you can have a look at the following thermometers out there.

1. Tempdrop

This is probably my new favorite! You wear the sensor in an armband on your upper arm and it tracks your temperature overnight. After a while it learns about your personal pattern and changes temperatures in hindsight if they seemed off.


  • No need to set an alarm to take your temperature
  • It syncs with your phone via bluetooth
  • Temperatures look a lot more stable because you are getting an average per night
  • Tempdrop has a GREAT app that allows you to track all the important fertile signs
  • The team is really helpful, they have great customer service. For example, I was sent a new (upgraded) frame when my previous one snapped.


  • Some women may find it uncomfortable to wear it at night (but through all the years, I can count those on 1 hand)
  • It’s a financial investment, though cheaper than some other overnight devices.
  • It needs a battery (lasts 6-9 months though)
  • Temperatures are a little less accurate than core body temperature devices.

I am so excited about Tempdrop, that I have become part of their affiliate program. To receive a 10% discount (even on top of sales) use coupon code WNW489MTTSPN5 on your purchase

2. El Cheapo

This type does not really have a name because it is off-brand. I have found these online in every country and funnily enough these all tend to be white and baby pink. It tends to retail for a maximum of $8 / €10 / £6. Often it is part of charting kits that include LH strips (ovulation peak tests) and pregnancy tests as well.


  • As said, it’s cheap! I would recommend everyone to start out with this first.
  • Usually has the option to choose between Fahrenheit and Celsius but otherwise make sure to pick the right one.


  • No back light
  • Beeps loudly (which is practical if you temp vaginally though!).
  • You have to remember to record the temperature soon after getting up because usually these thermometers don’t have a memory setting beyond 1 reading.

3. OvuSense

This is such an interesting one. The market is moving more and more towards core body sensors that measure your temperature several times at night to give you an average reading in the morning. Research shows  that these are the most accurate sensors out there!

Check out my review video on OvuSense below, or head on over to the review article.


  • You don’t have to wake up (early) to take your temperature. Also no more accidentally getting up before you take your temperature.
  • It can tell you IN CYCLE that you are about to ovulate! The only sensor that I know of that can do this.
  • It’s really well researched.
  • You get an average of a temperature per night so for most women that means bye bye erratic temperatures that are impossible to interpret!


  • It comes at a price. Starting at £99 with on top of that a membership fee for the use of the app.
  • Being a vaginal sensor, it isn’t for everyone.
  • The app doesn’t use any LH test or cervical mucus/position information to determine your fertility.

4. Wink & Priya Sensor from the people at Kindara

Maybe you fin my video:  a comparison between Wink & Femometer. But sadly Wink doesn’t exist anymore. Instead Kindara now has Priya sensor, which is a vaginal sensor. I’ve tried to get it for ever but nobody at their helpdesk is replyinh.

5. Femometer

I love the name of this thermometer, a thermometer for the female: Femometer.

Their video – which is very entertaining by the way – explains really well how it works.


  • Syncs with phone via bluetooth
  • It’s cheaper than Wink: $49 including shipping!
  • This one doesn’t really count but hey I’ll mention it anyway: it comes in 4 super cute colors (whatever helps you remember to temp right?)
  • The app is so fun and extensive
  • Syncing happens quickly with the app


  • The readings of the thermometer were not usually the same as on my boring thermometer or on my Wink, so I find it hard to trust.
  • It needs a battery
  • Predicting fertility was not accurate at all. Even after several cycles for me it either pinpointed ovulation too early or too late.
  • It has no display
  • It needs GPS on to download temperatures to your phone

You can also watch this video in which I am comparing Femometer with Kindara Wink.

6. Ava

This is not technically a thermometer but a watch that measures several things including temperature to confirm ovulation. I have not used it myself yet but can say the following about it.


  • No need to set an alarm to take your temperature, woohoo!
  • It syncs with your phone via bluetooth
  • It measures more things than just your temperature, and the company claims that their algorithm helps you identify an average of 5.3 fertile days per cycle at 89% accuracy. A clinical study was even done.


  • It costs a lot of money: €249 excluding shipping
  • Some women may find it uncomfortable to wear a watch at night
  • I could not find it on the website, but I assume that since the other parameters that are used to predict your fertile window are individual to every woman, it may take a few cycles for the watch to learn to predict accurately4

7. Oura

This is a ring you wear that syncs with your phone. It’s actually more of a health device than a fertility device but by connecting it through the Natural Cycles app, you can use it to track ytour temperature and ovulation too.


  • Comfortable ring to wear all day to get you a 24h average temp
  • No need to set an alarm to take your temperature
  • Syncs with your phone via bluetooth
  • Tracks more than just your temp (also sleep and heart rate, workouts etc.)
  • Only need to charge it every few days and through USB connector


  • High initial investment (starts at 350 EUR)
  • To use it with Natural Cycles you need to pay for an additional monthly membership to both Oura and Natural Cycles, it really adds up
  • The Natural Cycles app isn’t very comprehensive so for a full pictures I’d recommend then adding the temperatures in Fertility Friend or another better charting app
  • Natural Cycles will sometimes discard a temperature they consider out of range… thanks, I prefer deciding on that myself7

So, are you ready to start charting? Then check out my free course Your Fertile Window!