Ovulation Calculator

Ovulation Calculator

Ovulation calculators, charts, and calendars are tools that attempt to predict when you might ovulate. These tools are based on the typical length of your menstrual cycle and the expected window for ovulation to help time sex for pregnancy. Likewise, if you’re taking any fertility medications, these tools can be used to suggest when you’ll be most fertile.

While helpful tools, ovulation calculators are not 100% accurate; other methods of ovulation detection, such as ovulation test kits, are more precise. But an ovulation calculator like the one below can help put you in the fertility ballpark.

Ovulation Calculator
When did your last period start?
E.g. 18/01/2020
Usually, how long is your cycle?
Cycles typically vary from 23 to 35 days
Estimate your ovulation day
likelihood of ovulating today
Due to your cycle length, unfortunately we can't estimate an ovulation probability. We recommend that you use a Digital Ovulation Test to accurately detect your most fertile days.
  *
Start of your last period
  20%
Likelihood of ovulating on this date
Change my informations
In partnership with Clearblue®.
Results are based on the information you have provided and data from the publication below: Sarah Johnson, Lorrae Marriott & Michael Zinaman (2018): “Can apps and calendar methods predict ovulation with accuracy?”, Current Medical Research and Opinion, DOI:10.1080/03007995.2018.1475348