Lesson 8 – How to Track Ovulation with Basal Body Temperature (BBT)


  • Learn which type of thermometer is ideal for taking BBT

  • Learn how to properly take your BBT

  • Learn what guidelines should be followed when taking your BBT

Major Points:

Follow specific guidelines when taking and charting your BBT, including:

  • Use an accurate thermometer (preferably a basal/fertility thermometer available at most drugstores and pharmacies).

  • Take your temperature each morning around the same time.

  • Take your temperature soon after waking, before getting up, and after a sufficient amount of sleep.

  • Record your temperature immediately.

  • Basal body temperature can be taken in-ear, vaginally or orally, but be consistent during each cycle.

How to properly take and chart your BBT

Having an accurate reading is crucial to the success of your BBT tracking. It’s best to use a designated digital BBT thermometer that gives a fast and precise reading. Most modern thermometers give an audible beep when they’re finished recording and deliver a digital temperature reading that’s easy to read. 

Having larger digital numbers can be helpful when trying to read the thermometer with tired eyes soon after waking. While some BBT thermometers will store your readings for you, we recommend tracking the readings yourself on a bedside notebook or on an online app assessable on your phone. 

If you wish to avoid the hassles of taking your BBT and recording it by hand, try the earbud device that does all the work for you. Options like YONO consists of an ear bud that can detect and record the temperature in the ear canal every five minutes as you sleep. All data is then automatically synced into an application on your smartphone. 

Try to establish a morning routine that consists of taking and charting your BBT soon after waking. It’s best to take your temperature at the same time each morning to form a habit. Missing temperature data can distort your BBT chart and make it more difficult to determine when you will ovulate. 

Guidelines to follow when taking your BBT

Following specific guidelines can help you chart your temperature readings more accurately for reliable results. Without guidelines, your chart may be hard to read and negatively affect your ability to detect ovulation. However, these guidelines may vary slightly due to real life situations. 

  • Take your temperature before getting out of bed in the morning as moving too much after waking can increase your BBT.

  • Take your temperature each morning at the same time.

  • Take your temperature after receiving at least three consecutive hours of sleep.

  • Keep your thermometer at your bedside to prevent you from leaving your bed to track your BBT.

  • Use the same thermometer during your cycle, only changing it if absolutely necessary. If you do have to use a new thermometer, note it in your chart.

  • Take your temperature vaginally or orally but be consistent during your cycle. If one method is unclear after a month, switch to the other method the following month.

  • Record your temperature directly after taking it so that you don’t forget. Write it in a notebook placed at your bedside or input the data in a fertility app on your smartphone.

  • If you use an electric blanket or heating pad at night, make note of its use in your chart. If you use it nightly, maintain a single setting.

  • Always take your temperature before going to the restroom, eating, or drinking. If you must wait to take your temperature, make note of it in your chart. If other special circumstances prevent you from following these guidelines, try to follow them as closely as possible and mark any inconsistencies in your chart.

  • In addition to charting your temperature, also record the time in which you took your BBT as this data is important for analysis.

Tracking and charting your basal body temperature is an effective way to detect ovulation and boost your odds of fertility. It takes just minutes a day to take and chart your BBT but the results can give you great insight on the best time to have intercourse to increase your odds of conception.