The Best Basal Thermometer (Updated 2019 Reviews)

A list of popular basal thermometers was reviewed to determine which ones were most accurate, provided fast results, and were user-friendly. We selected these thermometers based on these criteria to help you find the best basal thermometer to chart your way to pregnancy.


If you need a very sensitive and clinically accurate thermometer that has the capacity to adjust to your actual body temperature, the Multi-Function Digital Basal Thermometer is the best one among the thermometers below. 

Unit of Measurement: Degree Fahrenheit and Celsius | Basal Body Temperature (BBT) Chart: Included | Battery: Replaceable | Warranty: 1 year

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What is Basal Body Temperature?

Basal body temperature (BBT) refers to your body temperature when you wake up before you perform any activity.

In addition to changes in the levels of luteinizing hormone and consistency of cervical mucus, women experience a change in their temperature during every menstrual cycle, which can be used to indicate ovarian function.

In general, women experience a 0.2–0.5°C increase in BBT shortly after ovulation and this persists until the next period.

As a result, a woman with ovulatory cycles experiences a biphasic shift in BBT during her cycle—a temperature shift that can be used to confirm ovulation.

Top Basal Body Thermometers Comparison Chart

Basal thermometers are designed to detect the small changes in temperature that occur during a woman’s cycle. Below is our list of top-rated basal thermometers.

1. Multi-Function Digital Basal Thermometer


This is an easy-to-use thermometer with a backlight monitor so you can see your reading clearly in a dark room. Although the Multi-function Digital Basal Thermometer will take slightly longer to display temperature than most thermometers listed here, it is designed to be very accurate.

Another great feature of this thermometer is its capacity to store up to 60 days memory, including the temperature, time, and date. You do not have to write down your data every time you measure your basal temperature.

With this innovative technology, you can simply scroll up or down to view your previous temperature measurements and draw it on your chart later.

2. Mabis Basal Thermometer For Natural Family Planning


The Mabis Basal Thermometer is generally recommended by clinicians for tracking ovulation. It is designed to conveniently monitor basal body temperature, as it can recall the last reading. Thus, day-to-day variations in temperature can be easily detected and tracked.

It is approved by the Food and Drug Administration (FDA) and has been shown to be clinically accurate in measuring BBT. It uses a replaceable alkaline button cell battery and comes with a pack of ovulation charts, enough for 12 cycles.

This thermometer is easy to use for charting ovulation and has the added benefit of coming with a 12-month supply of ovulation charts. Unlike some digital thermometers, it beeps quietly when turned on and when it is done reading the temperature.


  • It provides quick results (usually within 60 secs).
  • It provides accurate results and measures temperature to the 1/100th of a degree, which is necessary for tracking and pinpointing ovulation.
  • Results are displayed on an LCD screen and are easy to read.
  • The thermometer has an in-built system that recalls your last temperature so that you can easily detect day-to-day changes in temperature.


  • The LCD display lacks a backlight, making it difficult to read results in a poorly lit room. 
  • The power button needs to be pressed hard enough to turn on the device.

3. iBasal Digital Thermometer


This FDA-approved digital thermometer is a perfect choice for women with irregular cycles. It measures temperature to the 1/100th of a degree and displays results in Fahrenheit.

The device can display your cycle day and even generate a graph of your ten previous readings. It uses a replaceable lithium battery and has a small screen that displays data using symbols.


  • It accurately measures basal temperature.
  • It can predict your fertile periods based on your BBT data, saving you the trouble of interpreting the data.
  • Its reminder alarm ensures that you consistently record your temperature at the same time every day.


  • It can be challenging to use, with some women having difficulties in properly setting the device.
  • Temperature can only be taken one hour before or after the alarm goes off. Thus, you might need to reset the alarm if you wake up at different hours on business days and weekends.
  • Once you fail to input data (cervical mucus, menses), you cannot enter them the next day.

4. iProvèn’s Clinical Basal Thermometer


Highly accurate, this clinical basal thermometer measures temperature to the 1/100th degree. It is also referred to as an Actual Body Temperature thermometer due to its capacity to accurately adjust to your actual body temperature.


  • It provides accurate results by slowing adjusting to your basal temperature and can take approximately one minute to display the result.
  • It beeps when it is done recording temperature.
  • It stores your last reading; however, you need to save it after measurement.


  • It lacks a backlight, making reading difficult in the dark.
  • It records temperature only in Fahrenheit and lacks a function to convert it to Celsius.

5. Wink by Kindara


Kindara has been around since 2014, and it has gained popularity among women trying to conceive. This thermometer is unmatched in terms of design. Its monitor is equipped with a backlight to help you read in low light situations.

This thermometer is designed to measure your oral BBT readings, which you can obtain within 20 seconds. With wink, you don’t need to record your temperature readings or worry about losing your data.

The thermometer, whose design is based on the Fertility Awareness Method, can be connected to an app, making it easier for you to chart your BBT readings efficiently and conveniently.

Additionally, the app permits you to connect and interact with other women, which is a plus if you’re new to the fertility awareness world.


  • It is convenient and easy to use.
  • It is highly accurate and measures temperature to the 1/100th of a degree.
  • The app is available for Android and iOS devices. All you need is enable Bluetooth on your mobile device so Wink can sync your temperature automatically with the app.
  • The thermometer is rechargeable, so you don’t need to worry about getting new batteries or replacing a dying thermometer.
  • The thermometer is so silent that even your partner won’t even know when you’re using it. Wink will vibrate gently in your mouth when it is done measuring your BBT.


  • It needs to be brought to room temperature before use The device should be handled with care because it isn’t solidly built.
  • It is expensive and might not be a good choice if you’re on a tight budget.

6. [email protected] Smart Basal Thermometer


The [email protected] Smart Basal Thermometer can help you if you are trying to conceive or avoid a pregnancy (especially if you do not wish to use hormonal contraception). This ovulation tracker allows you to pinpoint your most fertile days so you are in control.

The device is easy to use and simply requires that you download the Premom App, sync via Bluetooth, and that’s it! After measuring your BBT, the app will automatically chart the information and calculate your ovulation date and your expected period date.

The [email protected] Smart Basal Thermometer is compatible with Apple and Android and is a good choice for women wishing to track their reproductive and menstrual cycles.


  • It is convenient and easy to use, as you don't need to manually record your data.
  • It is highly accurate and measures temperature to within ± 0.09°F/ 0.05°C.
  • The Premom Ovulation Calculator app is available for Android and iOS devices.
  • The thermometer uses a watch battery that has a power life of about three months.
  • The thermometer beeps gently when it is done recording.
  • It possesses a backlit display for easy reading in the dark.


  • The app should be open if you need your data to be automatically recorded to the app.

7. Non-Mercury Glass Basal Thermometer


This lab-certified glass thermometer is a mercury-free device that is designed for use in charting ovulation. The thermometer uses a liquid alloy that is considered safe contrary to mercury, which is reportedly toxic and associated with health hazards.


  • It measures temperature accurately to the 1/10th degree.
  • It comes with a magnifying case to ease reading.
  • It can be easily cleaned with soap and water.
  • No need to worry about replacing batteries.
  • Works well for oral, rectal, and vaginal temping. However, you want to make sure you do not use it orally after using it rectally.


  • It can break if accidentally dropped.
  • It takes long to read (approximately 5 minutes).
  • It has to be shaken prior to measurement.

8. Geratherm Basal Mercury Free Thermometer


This German-made glass thermometer is designed to for women to track their fertility. This highly sensitive thermometer is safe in that it doesn’t contain mercury.

The calibration strip is easy to read and it even has a magnifying glass to enlarge the enlarge the temperature display and facilitate reading. Also included with the thermometer is a BBT chart to record your temperature readings.

This thermometer is approved by the FDA. You can use it to take your BBT orally or rectally, but have to use one method consistently to avoid errors. The thermometer can be easily and safely disinfected or sterilized after use. 


  • It is very sensitive.
  • It is very straightforward to use.
  • The magnifying glass makes it easier to read the calibration strip.


  • The liquid can be particularly difficult to shake down after use.

How to Find the Best Basal Thermometer: Things to Consider When Buying One

1. Does the thermometer have a memory recall?

With the recall feature, you don’t need to note down the temperature immediately after taking it. You can do that later when you turn on the device, and it shows you the last recorded value.

2. Does it beep to indicate when the thermometer has finished recording?

It is not unusual to fall back asleep when you’re taking your temperature, so the beeping sound might just help to waken you when the device has finished measuring your temperature.

3. How much does the device cost?

Thermometers come in a vast range of prices, depending on the type and brand. Higher brand names tend to be more expensive (up to $60), but you can get a good basal thermometer for $20–30.

Also, consider reading reviews before deciding to purchase a cheaper brand just so you don’t end up with a thermometer that would last only a couple of months.

4. Does the thermometer measure to at least the 1/10th of a degree?

This is to ensure that it can accurately measure the small changes in the temperature that occur during a woman’s cycle and therefore help in determining when ovulation occurred.

5. Do you wish to purchase a glass or digital BBT thermometer?

Both types have their advantages and disadvantages, which you should consider before deciding which to buy. In the next section, you can read the pros and cons of both types.

Types of Basal Thermometers

Digital thermometers


  • Typically measure temperature within 30 to 60 seconds.
  • Some have a display screen with backlight, making it easy to read temperatures in a poorly-lit room.
  • They cannot break easily.


  • They use batteries, which should be changed when recommended.
  • Some devices are not waterproof.
  • They might display faulty readings, especially when the batteries start to run down.

Glass thermometers


  • They measure temperature accurately. Mercury has a high sensitivity and thermal conductivity and is preferable over other spirit-filled thermometers; however, mercury can be a toxic chemical and care should be taken when handling mercury-filled thermometers.


  • They are more difficult to use and have to be shaken before each use.
  • They can easily break if accidentally dropped.

Tips for Use

If you’re trying to conceive and planning on charting your temperature, you need some tips to determine when you’ll probably ovulate. Read our previous post to find out more about how to use a BBT thermometer to get pregnant.

Temperature Measurement Sites

Body temperature measurement sites for basal thermometers commonly include the mouth (oral) and deep body (rectal and vaginal).

Your temperature reading will vary if taken at different sites, so you must use one method consistently to avoid getting inaccurate results.


Most women prefer this method for the sake of convenience. Since temperature variations exist within the oral cavity, i.e., lower temperature in the front of the tongue and higher in the back, you need to make sure you use your BBT thermometer as recommended by the manufacturer.

You need to take measurements with your mouth closed and leave the thermometer longer, especially with a glass thermometer, which might require up to three minutes to accurately measure your BBT.


Some women feel comfortable measuring their BBT vaginally. However, vaginal BBT measurement is not advisable for women with vaginal infections.

Given that the vagina is very rich in bacteria, you should always clean your thermometer after each use if you plan to measure your BBT vaginally. (It is best to follow the manufacturer’s cleaning instructions.)


This is the least hygienic method of measuring BBT, albeit the one that provides the most stable readings. If you plan to use this method, it is highly recommended that you disinfect or sterilize your thermometer after each use.

Frequently Asked Questions about Basal Thermometers

1. How do you use a basal body thermometer?

  1. It is essential that get at least three hours of uninterrupted sleep every night so that you get an accurate reading.
  2. Take your temperature first thing when you wake up. By first thing, that means even before you get out of bed or do anything else such as brushing your teeth, eating, drinking, or smoking.
  3. Use the thermometer as indicated by the manufacturer. This means that you should have read the instructions of the manufacturer so that you understand how to use it to obtain the best results.
  4. Some thermometers beep when they’re done measuring your BBT, while others do not. If you’re unsure about how long you should leave your thermometer in place, a period of five minutes is enough for the device to measure your temperature.

2. What is the best way of measuring basal body temperature: oral, vaginal, or rectal temperature?

Any of the routes (oral, vaginal, or rectal) is fine, but use the method that you find convenient. As mentioned above, many women find that it is more convenient to measure their BBT orally.

3. What is the best basal thermometer with app?

There are so many basal thermometers that work alongside an app. Most of the apps that work with BBT thermometers also monitor other fertility signs such as changes in cervical mucus or cervical position.

In our list above, Kindara is the winner when it comes to a basal thermometer with app. You can read more about other fertility tools that track BBT and work with an app such as Femometer, Ava bracelet, and Natural Cycles.

4. Is a basal thermometer the same as a regular digital thermometer?

No, it is not. Although BBT and regular digital thermometers work in the same way, they are different in terms of their accuracy and purpose.

A BBT thermometer is more accurate than a regular digital thermometer. A BBT thermometer is accurate to 0.1 degree F whereas a regular digital thermometer is accurate to 0.2 degrees F.

Small changes in BBT, typically in the range of 0.4 to 1.0 F degrees during a woman’s cycle, are required to predict ovulation. Thus, the increased accuracy of a BBT thermometer permits you to chart your BBT more accurately than with a regular digital thermometer.

5. Can I use an ear thermometer / forehead thermometer to measure my BBT?

Basal body temperature can be taken in-ear; however, you need to use the correct device to measure your basal temperature. Although you can use a regular ear thermometer, it won’t give results as accurate or specific as a thermometer designed to measure BBT. Additionally, you would have to record your temperature readings manually.

If you’re looking for a hassle-free way of taking your BBT with an in-ear BBT thermometer, you may want to try the YONO earbud device from YONO Labs.  This device consists of an earbud that provides continuous body temperature data by measuring the temperature in your ear canal every five minutes throughout your sleep. The data are then synced with the YONO app on your smartphone.

We’ve not had the opportunity to check out this device, so we cannot comment on its accuracy. If you’ve tried it or know anyone who has used it, please drop us a comment below and share your experience so that other women can learn about this device.

We’ve not come across a forehead thermometer designed to track BBT. If you’re planning to use a forehead to track your BBT, you should note that a forehead thermometer is generally 0.5°F (0.3°C) to 1°F (0.6°C) lower than an oral temperature. So, you if you’re using a forehead thermometer, you should be consistent. Don’t use it on some days and switch to another thermometer type. You are sure to get inaccurate results if you do this!


With the various types of BBT thermometers available on the market, you might not know which one to choose. This post is intended to help you understand more about thermometers and how to choose one that might suit your needs.

It is necessary that you choose a reliable thermometer so that you can predict when you’ll ovulate and consequently increase your chances of getting pregnant. You might want to consider the higher quality brands since they have been reported to be more accurate and reliable.

While the accuracy of modern thermometers is unmatched, we have included at least one top glass thermometer in our review to help you decide whether this might be just what you are looking for in a basal thermometer.

Further Reading

Ayoola AB, Slager D, Feenstra C, Zandee GL. A Feasibility Study of Women’s Confidence and Comfort in Use of a Kit to Monitor Ovulation. J Midwifery Womens Health. 2015 Sep-Oct;60(5):604-9. doi: 10.1111/jmwh.12347. Read the article.

Wark JD, Henningham L, Gorelik A, Jayasinghe Y, Hartley S, Garland SM. Basal Temperature Measurement Using a Multi-Sensor Armband in Australian Young Women: AComparative Observational Study. JMIR Mhealth Uhealth. 2015 Oct 5;3(4):e94. doi: 10.2196/mhealth.4263. Read the article.

McLachlan RI, Yazdani A, Kovacs G, Howlett D. Patient education. Basal body temperature chart. Aust Fam Physician. 2005 Mar;34(3):139-40. Read the article.

Weischer M, Friis-Møller A, Bremmelgaard A. [Measurement of basal temperature with the Tempadot disposable thermometer for oral use]. Ugeskr Laeger. 1991 Dec 9;153(50):3538-40. Read the article.

Collins WP. The evolution of reference methods to monitor ovulation. Am J Obstet Gynecol. 1991 Dec;165(6 Pt 2):1994-6. Read the article.


Hi! Thanks for visiting. I'm a science geek and proud mom of two adorable kids. I love to research, learn, and write about personal improvement, healthy living, and fertility. On this site, I'll be reviewing the best fertility tests and discussing tips to help couples trying to conceive. I appreciate you visiting our website, and I'd be glad to answer any questions you may have.

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