Free Ovulation and Period Calculator
Enter the first day of your last period and your cycle length.
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How to do it
- 1Choose your settings
Fill in the details or pick the options you need.
- 2See the result
The preview updates right away as you change things.
- 3Download or save it
Save the result to your device. Nothing is sent to or stored on a server.
About this tool
Estimate when you are most likely to ovulate. Enter the first day of your last period and your usual cycle length and see the next three cycles: the expected period, the ovulation day and the fertile window. Cycles vary, so this is an estimate and it is not a method of contraception.
Frequently asked questions
How is ovulation estimated?
About 14 days before the next period starts. The fertile window is the five days before ovulation and the day after.
Can I use this to avoid pregnancy?
No. It is only an estimate. Speak to a doctor about contraception.
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