How do ovulation calculators work out your most fertile period?

Fertility calculators help to estimate the day of ovulation and, therefore, the days when you are most likely to get pregnant. However, these types of tools are more accurate when the menstrual cycle is regular.These calculators should not be used as a method of contraception.
Egg and sperm donation magazine

Ovulation Calculator: Estimate your most fertile days

How to calculate your fertility window - Quora

How to calculate ovulation? Methods, fertility help & information

When in the month are women and men most fertile? » British Fertility Society

How to Determine Your Most Fertile Day to Conceive: 7 Steps

6 Ways to Calculate Your Ovulation - wikiHow

Check Ovulation Calculator & Calendar

Calculating Your Menstrual Cycle To Find Your Most Fertile Days

How to Identify Your Most Fertile Days of the Month? - Clearblue