Get in Sync with Your Cycle: The Science Behind BBT Charting for Fertility

If you're trying to conceive or just trying to get to know your cycles, you've probably heard about basal body temperature (BBT) charting. This is a method of tracking your body temperature throughout your menstrual cycle to help predict when you ovulate. While it may sound like a lot of work, BBT charting can be an incredibly helpful tool for improving your chances of conceiving. Let's dive into the science behind BBT charting and how it can benefit your fertility journey.

What is Basal Body Temperature Charting?
Your basal body temperature is your body's temperature at rest, typically measured first thing in the morning before you get out of bed. By tracking your BBT every day throughout your menstrual cycle, you can see patterns in your temperature that can help you predict when you're ovulating. This is because your BBT typically rises slightly after ovulation due to an increase in progesterone. 

Why is BBT Charting Helpful for Fertility?
Knowing when you ovulate is crucial for conception, as you can only get pregnant when an egg is released from your ovary and travels down your fallopian tube. By tracking your BBT, you can get a better understanding of your cycle and when you're most likely to conceive. BBT charting can also help identify any issues with your cycle, such as irregular ovulation or a short luteal phase, which can affect your ability to conceive.

Tips for Accurate BBT Charting
To get the most accurate readings, there are a few things you can do to improve your BBT charting:
  • Take your temperature at the same time every day, ideally first thing in the morning before getting out of bed. Take it before taking off covers, talking or drinking anything for the best result.
  • Use a proper basal body thermometer, these have two decimal places so are more accurate for measuring small changes in temperature.
  • Record your temperature immediately after taking it, a fertility tracking app is the best way to do this. You can find a range of paid or free options depending on what you're after. They will let you know automatically when you have ovulated based on a well tested algorithm, or can let you know if you haven't ovulated. 

The Science Behind BBT Charting
Research has shown that BBT charting can be an effective tool for predicting ovulation and improving fertility. A study published in the Journal of Fertility and Sterility found that BBT charting was a reliable method for predicting ovulation in women with regular cycles. Another study published in the International Journal of Fertility and Sterility found that BBT charting combined with cervical mucus tracking was more accurate for predicting ovulation than BBT charting alone.

What Should Your BBT Chart Look Like?
When tracking your BBT, it's important to know what to expect in terms of patterns and trends. A typical BBT chart should show a pattern of low temperatures during the first half of your menstrual cycle, which should increase by about 0.3 celsius and stay elevated for the remainder of your cycle. So if your pre ovulation temperatures were around 36 degrees celsius, they will jump to around 36.3 after ovulation. It's important to keep in mind however that every woman's BBT chart is unique and there may be some variations from month to month. What's most important is to look at the overall trend of your chart rather than individual temperatures. Ideally, your BBT chart should show a clear shift from low to high temperatures, indicating ovulation has occurred. If you see a consistent pattern of low temperatures without a clear temperature shift, this may indicate that you are not ovulating regularly or at all.


BBT charting is a simple yet effective method for improving your chances of conceiving. By understanding your cycle and predicting when you're most likely to ovulate, you can time intercourse to maximize your chances of getting pregnant. So, grab a basal body thermometer and start tracking – you never know, it may just be the key to unlocking your fertility journey.