How this family planning method works

How Does the Standard Days Method of Family Planning Work?

The Standard Days Method® is a fertility awareness-based family planning method that identifies a fixed fertile window for women with cycles that are between 26 and 32 days long. For women with cycles in this range, the method identifies days 8 through 19 as potentially fertile days. A user simply tracks the start date of her period and the days of her cycle to know if she is on a day when pregnancy is possible or not.

Researchers at the Institute for Reproductive Health at Georgetown University developed this family planning method and tested it in large-scale clinical trials. It is proven to be more than 95% effective at preventing pregnancy and with the right tools, is very easy to use. See more about this research and the scientific origins of this family planning method in the Research section of this website.

Millions of women use family planning tools based on the Standard Days Method to prevent pregnancy or plan pregnancy because it is:

  • More than 95% Effective
  • Side-Effect Free
  • Easy to Use
  • Inexpensive
  • Educational & Empowering


Tools Based on the Standard Days Method of Family Planning

CycleBeads®, iCycleBeads™ smartphone apps, and the new CycleBeads® Online service are all patented tools based on the Standard Days Method of family planning. These tools are designed to help a woman track her cycle, and monitor the key information required to use this family planning method effectively. See the product pages for CycleBeads, iCycleBeads smartphone apps, and the new CycleBeads Online service to see detailed information about how each of these tools work. 

How to Prevent Pregnancy with CycleBeads 

If a woman wants to prevent pregnancy using this family planning method, then she should avoid intercourse or use a back-up birth control method such as condoms during her fertile days (days 8-19). The patented CycleBeads tools help a woman use this method by tracking her cycle, identifying her fertile and non-fertile days based on when her period started, and confirming that her cycles are in range for effective use of this family planning method.

How to Plan Pregnancy with CycleBeads 

If a woman wants to plan pregnancy, she and her partner should target her fertile days and have intercourse at least every other day during this time. Some researchers have said that couples should have intercourse every other day (vs. every day) to ensure that sperm counts are high. Others have found that sperm counts are adequate even if a couple has intercourse every day during the fertile time and that success rates may be slightly higher.


Who Can Use This Family Planning Method?

This family planning method is most effective for women with menstrual cycles that are regularly between 26 and 32 days long. The CycleBeads and iCycleBeads tools will help a woman determine if her cycles are in this range and that they stay in this range. Women with cycles outside this range should use a different method of family planning to prevent pregnancy. If you are uncertain about the length of your cycle, please see How to determine the length of your cycle in our FAQ section to find out more.

Take the CycleBeads Self-Screen


1 According to analysis of data from the World Health Organization, 80% of women have cycles in the 26-32 day range.
2 The Institute for Reproductive Health is a research organization established at Georgetown University Medical Center, and working in reproductive health for +25 years.