Period Calculator & Menstrual Cycle Tracker
Track your menstrual cycle and predict future periods
Last Menstrual Period
Cycle Information
days
days
Calculation Options
days
Your Menstrual Cycle Results
Based on your cycle information
Next Ovulation: January 29, 2024
Fertile Window: January 24 - January 30, 2024
Cycle Calendar
Showing next 6 menstrual cycles
| Cycle | Period Start | Period End | Ovulation Date | Fertile Window | Next Period |
|---|
Current Cycle Overview
| Date | Day of Cycle | Phase | Fertility | Notes |
|---|
About Menstrual Cycle Tracking
The menstrual cycle is the regular natural change that occurs in the female reproductive system that makes pregnancy possible. The cycle is required for the production of eggs and for the preparation of the uterus for pregnancy.
Menstrual Cycle Phases
| Phase | Days | Description | Key Events | Fertility |
|---|---|---|---|---|
| Menstrual Phase | 1-5 | Period bleeding, uterine lining sheds | Menstruation occurs | Low |
| Follicular Phase | 6-13 | Follicles develop in ovaries, uterine lining rebuilds | Eggs mature in follicles | Increasing |
| Ovulation Phase | 14 | Mature egg released from ovary | Ovulation occurs | Peak |
| Luteal Phase | 15-28 | Uterine lining prepares for pregnancy | Corpus luteum forms | Decreasing |
Cycle Length Variations
| Cycle Length | Classification | Ovulation Day | Characteristics | Prevalence |
|---|---|---|---|---|
| 21-24 days | Short Cycle | Day 7-10 | Early ovulation, shorter luteal phase | 15% of women |
| 25-30 days | Average Cycle | Day 11-16 | Regular ovulation, typical luteal phase | 60% of women |
| 31-35 days | Long Cycle | Day 17-21 | Later ovulation, normal luteal phase | 20% of women |
| 36+ days | Irregular/Long | Variable | Irregular ovulation, may indicate issues | 5% of women |
Understanding Your Cycle
- Cycle Length: Number of days from the first day of your period to the day before your next period starts (typically 21-35 days)
- Period Length: How long your bleeding typically lasts (usually 3-7 days)
- Luteal Phase: Time between ovulation and the start of your next period (typically 12-16 days, usually 14 days)
- Ovulation: Usually occurs about 14 days before your next period starts
- Fertile Window: 5 days before ovulation through the day of ovulation (sperm can live up to 5 days)
Important Notes
- These calculations provide estimates - actual cycles may vary
- Cycle length can vary from month to month due to stress, illness, travel, or other factors
- Track your actual cycles for several months to determine your personal pattern
- Consult a healthcare provider if you experience significant changes in your cycle or have concerns
- This calculator is for informational purposes and should not replace medical advice