Basal Body Temperature Chart

Learn how to track fertility using a Basal Body Temperature Chart. Download our free PDF today!

By Audrey Liz Perez on Apr 08, 2024.

Fact Checked by Ericka Pingol.

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What is a Basal Body Temperature?

Basal Body Temperature (BBT) is the lowest body temperature attained during rest, usually measured right after waking up and before any physical activity. Tracking BBT is a common method used to identify ovulation and determine a woman's fertile window. By recording BBT daily, women can identify the slight temperature increase after ovulation.

A is a tool that helps women track their BBT and cervical mucus changes over time. Plotting BBT data on a chart makes it easier to notice patterns and understand fertility signs. Monitoring BBT is a cost-effective, non-invasive method that can be helpful for women trying to conceive or avoid pregnancy.

What is BBT?

BBT, or your basal body temperature, is your body temperature when you are at complete rest. To test for your BBT, you should take your temperature in the morning before you get out of bed or move.This also means that you cannot go to the bathroom, as any of these movements may result in your temperature rising. Temperatures can rise from around 0.2-0.6 °C (or 0.5-1.0 degrees Fahrenheit) which is not a drastic change.

It is important to note that your BBT can fluctuate depending on various factors. This includes hormones. When ovulating, your progesterone hormone can cause increase in body temperature, and this can be maintained at a high rate throughout the menstrual cycle. Before your period begins, the progesterone hormone can drop as well (unless you are pregnant).

BBT can also fluctuate depending on illnesses, medications, hot weather, shift work, travel, alcohol consumption, and changes in sleep patterns.

You should start charting on the first day of your period, and continue to take your temperature throughout your entire menstrual cycle. As you gain experience, you can skip the first few days of your period and start taking body temperature measure around the fifth or seventh day.

It is also important to note that this method is not perfected, as it only indicates to you after you have released an egg, which means the fertility window has closed for that menstrual cycle.

BBT Phases

In the menstrual phase, your BBT should be between 97 and 98 degree Fahrenheit. In the follicular phase (the first day of your period until the last day of ovulation) should be the same, but one day before ovulation, this may dip below by 0.5 degrees Fahrenheit. For ovulation, BBT baseline temperature may rise above by 0.5 to 1.0 degree Fahrenheit. In the luteal phase (sometime referred to as the two week wait), your BBT may return to a lower range.

Measuring BBT

There are three important factors that you should consider for taking accurate BBT measures.


Make sure to take your temperature at the same time every morning (although 30 minutes wiggle-room is acceptable). This allows for greater consistency and more accuracy in results.


Restrict movement by avoiding walking round, sitting up, or going to the bathroom. As soon as you wake up, you should take your temperature.


Inconsistent sleep schedules can affect temperature results. Make sure you have around 3-4 hours of uninterrupted sleep!

What To Look For

The key pattern to take note of are any temperature increases or decreases. Your temperature can change across your cycle, however, there should be an obvious pattern emerging after ovulation. Temperatures should be, on average, lower than they are after ovulation. If you notice three higher than average temperatures in a row, you can likely conclude that ovulation occurred the day before the first high temperature.

Cervical mucus is also a useful indicator. If you noticed cervical mucus on the days leading up to the temperature rise, you can likely conclude that ovulation occurred on the day before.

A sudden decrease in temperature on the day of ovulation, before the rise, may indicate that you should have sexual intercourse on that day.

BBT for No Ovulation

If you are not ovulating, you cannot become pregnant. However, if this an irregular pattern, you may have a risk of infertility. Lack of ovulation is commonly called anovulation, and is a common contributor to female infertility. This can be sometimes fixed with fertility drugs such as Clomid.

Pregnancy and BBT

BBT can indicate pregnancy, but you should always take a pregnancy test to be certain.

A BBT chart can determine if you have had sex on your most fertile days, as well as indicate to any implantation dips.This is not a sure-fire sign of pregnancy, but can be indicative in some cases.Additionally, a BBT chart can highlight any triphasic temperature patterns that suggest a higher progesterone which may occur in pregnant women. BBT charting is also useful for assessing long luteal phases, where two days beyond the normal range may indicate pregnancy.

If your BBT stays up for 18 days or more, this could be an early sign of pregnancy. This may prompt you to take a pregnancy test. No specific temperature itself indicates pregnancy.

Printable Basal Body Temperature Chart

Download this Basal Body Temperature Chart to help women track their BBT over time.

How does this Printable Basal Body Temperature Chart work?

A printable Basal Body Temperature Chart is a simple and effective way to track fertility. Follow these steps to fill out the chart accurately:

Step 1: Record the Day of the Cycle

The first day of your last menstrual period (LMP) is considered Day 1. Write down the number of days since your LMP in the "Day of Cycle" column.

Step 2: Fill in the Date.

Write the corresponding date for each day of your cycle in the "Date" column.

Step 3: Record your BBT.

Measure your BBT each morning before getting out of bed and after at least three hours of uninterrupted sleep.

Use a BBT thermometer for accurate readings. Record the temperature in Fahrenheit (°F) and/or Celsius (°C) in the "BBT" column.

Step 4: Observe and record Cervical Mucus

Check your cervical mucus daily and record its consistency using terms like "dry," "sticky," "creamy," "watery," or "eggwhite" in the "Cervical Mucus" column.

Step 5: Use an Ovulation Predictor Kit (OPK).

If you are using an OPK, follow the manufacturer's instructions, and record the results as "positive" or "negative" in the "Ovulation Predictor Kit (OPK)" column.

Step 6: Make additional Notes

Record any relevant information, such as menstruation, spotting, or anything else you feel is important to track in the "Notes" column.


A Basal Body Temperature Chart is based on identifying patterns and fertility signs. Look for the following:

  • A sustained increase in BBT (0.5°F to 1°F or 0.3°C to 0.6°C) after ovulation,
  • Consistent low temperatures during the follicular phase (before ovulation) and higher temperatures during the luteal phase (after ovulation)
  • Changes in cervical mucus consistency, with the most fertile mucus being eggwhite in appearance

Basal Body Temperature Chart example (sample)

Refer to the Basal Body Temperature Chart in this guide for a sample table with example data. This sample will help you understand how to fill in the chart and interpret the results.

Download this Basal Body Temperature Chart Example (Sample) here:

Basal Body Temperature Chart example (sample)

When to use these Basal Body Temperature Assessments?

Basal Body Temperature assessments can be used in various scenarios, such as:

Trying to conceive

Women trying to get pregnant can use BBT tracking to identify their fertile window and plan intercourse accordingly for a higher chance of conception.

Natural birth control

Women who want to avoid pregnancy without hormonal contraceptives can use BBT tracking as a natural family planning method.

Understanding your cycle

Monitoring BBT can provide insights into the regularity of your menstrual cycle and hormonal balance.

Identifying potential fertility issues

Irregular patterns in BBT charts may indicate potential fertility issues that should be discussed with a healthcare professional.

Benefits of these free Basal Body Temperature Chart templates

Using a Basal Body Temperature Chart is an effective way to monitor your fertility and take control of your reproductive health. These free templates offer a range of benefits, from ease of use to cost-effectiveness, empowering women to make informed decisions about family planning. 

This section will discuss the advantages of using these templates and how they can improve your understanding of your body's natural fertility patterns.

Easy to use

The simple table format makes recording and tracking your BBT data easy.


BBT tracking is a low-cost method for understanding your fertility patterns.


BBT monitoring does not require any invasive procedures or medications.

Provides insights into fertility

Identifying your fertile window can help you plan or avoid pregnancy more effectively.

Empowers women

BBT tracking enables women to take control of their reproductive health and make informed decisions.

Supports early detection of potential issues

Irregular BBT patterns may indicate hormonal imbalances or fertility issues that should be addressed with a healthcare professional.

Why use this Basal Body Temperature Chart app?

Using the Carepatron Basal Body Temperature Chart app provides several advantages:

  • Digital tracking: Record and store your BBT data electronically, eliminating the need for paper charts.
  • Accessible from anywhere: Access your BBT data on your smartphone, tablet, or computer.
  • Data analysis: The app can help you analyze your BBT data and identify patterns more easily.
  • Secure storage: Your sensitive health information is securely stored and protected.
  • Share with healthcare providers: Easily share your BBT data with fertility specialists, gynecologists, or health coaches for professional guidance.
Practice management software benefit
Who created the Basal Body Temperature Chart?
Who created the Basal Body Temperature Chart?

Commonly asked questions

Who created the Basal Body Temperature Chart?

BBT tracking has been around for decades, with various charts and apps developed by fertility specialists, reproductive health experts, and app developers.

How to use the Basal Body Temperature Chart?

Follow the step-by-step guide in this article to fill out and interpret the Basal Body Temperature Chart accurately.

How to interpret the Basal Body Temperature Chart results?

Look for patterns, such as a sustained increase in BBT after ovulation and changes in cervical mucus consistency, to determine your fertile window.

What is the best way to take body temperatures?

It is preferred to use a thermometer orally, vaginally, or rectally. Whichever way you choose, it is important to choose the same way every time for accurate results.

What does BBT look like for pregnant vs. non-pregnant women?

BBT results for pregnant women may show arise in body temperature that stays up for 18 days or more. If this does not go back down, this may be a sign of early pregnancy. This rise is due to the increase in production of the hormone progesterone.

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