How To Use BBT To Confirm Ovulation – Simplified Expert Tips

If you’re not familiar with all of the fertility-related acronyms, we’re going to run you through the process of tracking your basal body temperature (BBT). This is one of our favorite methods of confirming ovulation. Although there are many methods that you can use to confirm ovulation, this method is safe, simple, and inexpensive. 

With LH-strip ovulation predictor kits (OPKs), there are many factors that influence your result, such as the time of day, how hydrated you are, and your own *normal* LH levels. Personally, we’ve experienced stress trying to determine whether or not the LH-line appeared or not! 

The basal body temperature method is easy to remember (done first thing in the morning), takes less time than OPKs, and allows you to be more in-tune with your menstrual cycle. It’s also up to 90% accurate when measurements are taken correctly! Let’s get started!

What Does My Menstrual Cycle Look Like?

bbt chart


Tracking your menstrual cycle is a great first step to getting to know your body better!

Before we jump right in to BBT charting, it’s important to have a basic understanding of how your menstrual cycle works. Your menstrual cycle begins and ends with your period. Keep in mind that your menstrual cycle is unique to you! Everyone has a different menstrual cycle. The average length of menstrual cycles is 28 days, but a healthy cycle can be anywhere between 21 and 40 days. Another key sign of a healthy menstrual cycle is consistency. Each month, your menstrual cycle should be within a day or two of your average cycle length.

Throughout your menstrual cycle, your hormones will rise and fall to help signal to your body to prepare to release an egg to be fertilized! Everyone’s cycle is different, but in general, your body likes to release an egg from your ovaries about 2 weeks before your next period. For example, if you have a 28 day menstrual cycle, you can expect to ovulate on day 14 of your cycle (+/- 3 days). Because there is some variability with the day that you will ovulate, it’s important to use science and technology to get a better idea of the exact day.

How To Create Your BBT Chart

Creating your chart is easy! The only tools you need are a thermometer (with at least one decimal place), a chart (download your free chart here), and a pen. We recommend keeping your chart and your thermometer by your bedside so you don’t accidentally forget!


When you wake up each morning, the first thing you will do is take your temperature – before eating, drinking, or walking around. By consistently taking your temperature as soon as you wake up, you will more accurately be able to confirm ovulation.

You will want to start tracking your temperature on cycle day 1 (when your period begins) and continue throughout your entire menstrual cycle. Once you get a better understanding of your cycle, you will be able to predict when you will ovulate during your cycle. 

Your chart may look something like this:

basal body temperature chart example

Using Your BBT Chart To Confirm Ovulation

When you ovulate, your basal body temperature (BBT) will slightly increase. Your body temperature increases because it starts producing progesterone after you ovulate. Progesterone is a hormone that helps thicken and prepare the uterine lining for a possible implantation of an embryo. On your chart, you should notice at least a 0.5 degree increase in your body temperature if you ovulated. Your temperature should also remain elevated for the next 3-4 days. Your chart may look something like this:

ovulation chart

Ovulation usually occurs 24-48 hours before the slight rise in basal body temperature. In the example above, the day before the rise is July 9th (7/9). Therefore, ovulation would have occurred 24-48 hours earlier (either on 7/7 or 7/8). 

By tracking your basal body temperature over several menstrual cycles, you can really get to know your body! This will help you predict which day during future cycles you will ovulate. Typically, your ovulation day is consistent month-to-month (within a day or two). For more information on timing intercourse in order to conceive, check out our short article here

If you’ve performed BBT charting and do not see the trends confirming ovulation, there may be a hormonal issue. The good news is that many ovulatory issues can be easily resolved! To help pinpoint which hormones are out of balance, take our fertility quiz!

Ready to check in with your hormone levels?