What is a BBT chart and how to start one: my guide to BBT Charting for ovulation, contraception, hormone health and cycle tracking.
You might have heard people talking about their BBT chart or temperature tracking and wondered what on earth it was. Should we all be doing it? Is it just for pregnant people or those using that Natural Cycles thing?
The truth is BBT (Basal Body Temperature) tracking is a fantastic way to get more information about your menstrual health and it only takes about 60 seconds a day!
Regular cycles usually show a biphasic temperature pattern with your core body temperature lower in the first half (before ovulation) and higher in the second half (after ovulation). By tracking your daily temperature you are not only able to pinpoint ovulation, but also keep an eye out for potential hormone imbalances, predict your period more accurately and even use it for contraception.
Watch: What is BBT Tracking and How to Do It Correctly
This article contains affiliate links – ad – Affiliate links do not change the price you pay but xameliax earns a small commission that enables us to continue writing useful, informative and free articles such as this one!
How to Create a BBT Chart
In order to create a personalised BBT chart you’ll need a thermometer that reads to 2 decimal places. Temp fluctuations are small but significant so a regular thermometer won’t do. They’re not expensive – this is the bbt thermometer I use and it’s under £10.
You need to take your temperature at the same time every day (give or take 30 minutes) and it needs to be the very first thing you do. The moment you sit up, get up or start doing things your body temperature will rise causing your reading to be inaccurate. So get into the habit of waking up and reaching over for your thermometer as soon as you open your eyes!
If you have a disturbed nights sleep, suffer an illness, travel to different time zones or drink alcohol these things can affect your BBT so be sure to make a note of those in case of abnormal fluctuations.
Once you have your temperature reading you will need to record your temperature either in your period tracking app, a specialised BBT tracking app or on a manual BBT Chart. And when you’ve taken your temperatures for a month or so you’ll be able to start looking for patterns!
What to use your BBT chart for
You can use the patterns in your BBT chart to pinpoint ovulation if you’re trying to conceive. Ovulation is signified by a sharp dip in temperature followed swiftly by a large jump in temps that stays elevated for 3 days or more. This can either be used to find your fertile window…or to avoid it if you’re using BBT tracking as conception!
You can also predict when your period may arrive with a dip in temps towards the end of your cycle, or a potential pregnancy if your temperatures stay high or jump even higher (also known as a tri-phasic BBT chart).
If you’re not getting a regular dip and rise to signify ovulation it may be a sign of a hormone imbalance or underlying problem. By taking your basal body temperature regularly and having this information in a chart, you can bring the data to your GP and talk in more detail about potential tests and options.
I’m a big believer that knowledge is power when it comes to our bodies and especially our menstrual cycles, so I love tracking my BBT and seeing the patterns unfold – it’s so easy but quite empowering. If you’re looking to go one step further in your quest for hormone knowledge there are also at home fertility tests that can be done to find out even more about your menstrual and fertility health. Take a look at my experience with Hertility here checking my hormones and my ovarian egg reserve.
Feel free to join me over on instagram @xameliax for more hormone chat & period tips!