Want to stay on top of your menstrual cycle? Our Period Calculator predicts your next period, ovulation, and fertile window based on your last menstrual period (LMP) and cycle length. Ideal for family planning, health monitoring, or managing cycle symptoms, this tool provides clear, calendar-based insights for the next six cycles.
A Period Calculator forecasts your menstrual cycle dates, helping you anticipate periods, ovulation, and fertile days. It offers:
Based on an average 28-day cycle, it assumes ovulation occurs ~14 days before the next period. Results are estimates, as cycles can vary due to stress, hormones, or health conditions.
The calculator uses your LMP and average cycle length to predict future periods and ovulation. Ovulation is estimated at 14 days before the next period, with a 6-day fertile window (days 10–15 for a 28-day cycle).
Example:
LMP: January 1, 2025
Cycle Length: 28 days
Next Period: January 29, 2025
Ovulation: ~January 15, 2025
Fertile Window: January 10–15, 2025
The tool generates a table and calendar for six cycles, adjusting for your specific cycle length (e.g., 21–35 days).
You’ll get:
✔ Dates for your next six periods
✔ Ovulation and fertile window predictions
✔ Visual calendar and table for easy tracking
Q1: How accurate is the Period Calculator?
✅ It’s an estimate based on average cycle lengths. Irregular cycles may reduce accuracy.
Q2: What if my cycle length varies?
✅ Use your average cycle length (e.g., 28 days). Track cycles for better estimates.
Q3: Can it predict ovulation exactly?
✅ It estimates ovulation ~14 days before your next period, but ovulation tests are more precise.
Q4: Is it useful for irregular cycles?
✅ It’s less accurate for irregular cycles. Consult a doctor for persistent irregularities.
Q5: Can it help with contraception?
✅ It identifies fertile windows but isn’t a reliable contraceptive method alone.
The menstrual cycle, typically 21–35 days (average 28), is driven by hormones like estrogen and progesterone. It includes four phases: menstruation (bleeding, ~3–7 days), follicular phase (preparing for ovulation), ovulation (egg release, ~day 14), and luteal phase (preparing for the next period or pregnancy). Our calculator predicts key dates based on your last menstrual period (LMP) and cycle length.
Using your LMP and average cycle length, the calculator forecasts:
Tracking helps you:
Irregular cycles (varying >7 days) may signal:
Consult a healthcare provider if cycles are consistently irregular or accompanied by severe symptoms.
This calculator assumes regular cycles and is less accurate for irregular ones. It’s not a substitute for ovulation tests or medical advice, especially for fertility or contraception purposes.
Source: Synthesized from gynecological research and ACOG guidelines, 2023.
Our Free Period Calculator empowers you to track your menstrual cycle with ease, predict periods, and plan for ovulation or health needs. Stay in tune with your body and take control of your wellness journey.
🚀 Start tracking your cycle today!
This Period Calculator content is independently researched and authored by me, based on gynecological research and ACOG guidelines.
Track your menstrual cycle to predict period and ovulation days, helping with planning and health monitoring.