What is Coverline?

When trying to get pregnant, it is a good idea to chart your basal body temperature to determine when and if you ovulated. Ovulation is associated with an increase in temperature -- a thermal shift -- revealing a typical biphasic curve. The cover line is a horizontal line drawn after ovulation to help differentiate temperatures before ovulation (low) and temperatures after ovulation (high). When your waking body temperature rises more than two-tenths of a degree higher than the previous six days, and it stays that way for at least two days, your cover line can be established. When your waking body temperature rises more than 0.2 or two-tenths of a degree higher than the previous six days, and it stays that way for at least two days, you can start drawing your cover line. This rise normally occurs during your thermal shift the day after ovulation. For example, a jump from 97.1 to 97.3 is a rise that is 0.2 or two-tenths of a degree higher.

The cover line is drawn after your temperature has risen because of ovulation and stayed up for at least 2-3 days. This is called a "sustained" elevation and indicates that ovulation has taken place. It is possible that prior to the rise, prior to ovulation, the temperature may have dropped for a day below what eventually will be the cover line. That one-day temperature should be ignored in order to create the cover line. Understanding how to chart your basal body temperature and establish a cover line is a useful skill in fertility charting.

Coverline and BBT Charting

The coverline is a horizontal line drawn in your basal body temperature BBT chart after ovulation has been established. ... read more »

Coverline - When Is It Being Drawn

When your waking body temperature rises more than 0.2 or two-tenths of a degree higher than the previous six days, and it stays that way for at least two days, you can start drawing your coverline. ... read more »

Setting Ovulation and Coverline Visually

How is a visual interpretation of ovulation and coverline done? ... read more »

Biphastic Curve

Your temperature may go up and stay up above the coverline for 14-16 days after ovulation. That is called a "biphasic curve". ... read more »

Coverline - What Is It?

How do I determine my coverline? ... read more »

Fertility Course Lesson 8: I Want That Coverline

The coverline is a horizontal line drawn after ovulation to help differentiate temperatures before ovulation (low) and temperatures after ovulation (high). ... read more »

Fertility Course Lesson 7: The Lowdown on Basal Body Temperature

Your basal body temperature, BBT, is your body's temperature at rest, when you have slept for several hours. The best time to take your BBT is first thing in the morning when you wake up. ... read more »

Fallback Temperature

A fallback temperature happens when your basal body temperature that was above the coverline drops for 1-2 days below the coverline. ... read more »

BBT - How To Do A Basal Body Temperature Chart

Learn how to chart your basal body temperature (BBT) ... read more »

Coverline - Temps to Overlook

The coverline is drawn after your basal body temperature has risen because of ovulation and stayed up for at least 2-3 days. ... read more »

Coverline: How To Draw It On Your Temperature Chart

How to draw a coverline when fertility charting. ... read more »