Enter your last period details and instantly get your next period date, fertile window, ovulation day, and a simple month-wise overview.
About This Period Cycle Calculator
This tool works as a menstrual period calculator, menstrual calculator, and period predictor combined into one simple system. By using your last period date, period length, and average cycle length, it estimates:
- Your next period start and end range
- Ovulation timing
- Fertile window
- Best days for intercourse when trying to conceive
- Month-wise cycle pattern
- Easy-to-follow color-coded calendar
It functions as a menses period calculator and menstrual flow calculator, helping you understand your rhythm and plan around important days with more clarity. It also works as an ovulation and fertile window calculator for periods, giving you helpful insights for both conception planning and general cycle awareness.
The predictions are calculated using the same standard formulas commonly used by health professionals, giving you a clear snapshot of your upcoming cycle phases.
Example Calculation
Below is an example based on:
- First Day of Last Period: 01/10/2025
- Period Duration: 5 days
- Average Cycle Length: 28 days
Period & Fertility Prediction
| Result Type | Estimated Dates |
|---|---|
| Next Period | 29 Oct – 2 Nov |
| Ovulation Day | 15 Oct |
| Fertile Window | 13 Oct – 17 Oct |
| Best Days for Intercourse | 13 Oct – 17 Oct |
Month-wise Overview
| Month | Period Dates | Ovulation | Fertile Window |
|---|---|---|---|
| October 2025 | 1 Oct – 5 Oct | 15 Oct | 13 Oct – 17 Oct |
| October 2025 | 29 Oct – 2 Nov | 12 Nov | 10 Nov – 14 Nov |
| November 2025 | 26 Nov – 30 Nov | 10 Dec | 8 Dec – 12 Dec |
| December 2025 | 24 Dec – 28 Dec | 7 Jan | 5 Jan – 9 Jan |
| January 2026 | 21 Jan – 25 Jan | 4 Feb | 2 Feb – 6 Feb |
Calendars help you visualize pattern changes, fertile days, and upcoming periods in a clear monthly layout.
Why Use This Tool?
This calculator helps you:
- Track regular or irregular cycles with ease
- Plan around travel, events, or lifestyle changes
- Understand when you’re most fertile
- Know when to expect symptoms and flow changes
- Monitor cycle patterns month by month
- Improve natural awareness of your reproductive rhythm
Note: These results are approximate and for personal tracking only.