Ovulation Calculator
Calculate your ovulation date and fertile window based on your last period and cycle length. Find the best days to conceive and plan the next 3 cycles ahead.
How to Use the Ovulation Calculator
Enter Your Last Period Date
Input the first day of your most recent menstrual period.
Set Your Cycle Length
Enter your average cycle length (21–35 days). Default is 28 days.
Adjust Luteal Phase
The luteal phase is 12–16 days. Default is 14 days and works for most women.
Enter Period Duration
How many days your period typically lasts (2–10 days).
Tap Calculate
Instantly see your ovulation date, fertile window, and next period date.
View Your Cycle Calendar
See your entire current cycle mapped day by day with color coding.
Plan Ahead
See the next 3 ovulation cycles to plan conception or avoid pregnancy.
Why Use Our Ovulation Calculator?
Accurate Fertile Window
Calculates your 6-day fertile window — the 5 days before and the day of ovulation.
Visual Cycle Calendar
Color-coded day-by-day view of your entire cycle with period, fertile, and ovulation days.
3-Cycle Forecast
See the next 3 predicted ovulation dates and fertile windows to plan ahead.
Customizable Inputs
Adjust cycle length, luteal phase, and period duration for personalized results.
Mobile Friendly
Works perfectly on any device — phone, tablet, or desktop.
100% Free
No sign-up, no limits — completely free forever.
