Ovulation Calculator
Calculate Ovulation Date, Fertile Window & Next Period
Enter your last period start date and average cycle length to find your estimated ovulation date, fertile window, and next period date.
🌸 What is Ovulation?
Ovulation is the release of a mature egg from the ovary. It typically occurs 14 days before the next expected period. The fertile window spans about 6 days: 5 days before ovulation through the day of ovulation, when pregnancy chances are highest.
📝 How to Use
- Select your last period start date
- Enter your average cycle length (typically 21-35 days)
- Click calculate
- View your ovulation date and fertile window
- Check the 3-month calendar for visual fertile period tracking
💡 Helpful Tips
- If your cycle is irregular, use the average of the last 6 months
- Use ovulation test strips (LH strips) for more accuracy
- Basal body temperature rises 0.2-0.5F after ovulation
- 2-3 days before ovulation have the highest conception rates
- Stress, travel, and weight changes can affect your cycle
❓ FAQ
It is fairly accurate for those with regular cycles, but individual variation exists. For better accuracy, combine with ovulation test strips or basal body temperature tracking.
Record your cycles for the last 6 months and use the average. If cycles vary by more than 7 days, consult a gynecologist.
The fertile window has the highest probability, but sperm can survive up to 5 days inside the body, so pregnancy is possible outside the calculated window.
📚 Local Method & Assumption Guide
Formula Logic
Core formulas use public finance, loan, ratio, and unit conversion standards.
Source Scope
References follow publicly available standards and country-level common practices.
Assumptions
Taxes, fees, rates, and limits vary by region and institution.
Result Interpretation
Use this result as a baseline scenario. For decisions, compare with your lender quote and local tax treatment.
Locale Preset
Currency: USD
Units: imperial
Tax logic: US payroll estimate
Regulatory Note
This tool uses regional presets for estimation. Contract terms and legal limits may differ by lender, bank, or local law.
Recommended Next Actions
- Compare at least 2-3 local providers before final submission.
- Re-check fees, tax treatment, and prepayment clauses in writing.
- Run a stress scenario with +1-2% interest and lower income.
Before a real financial decision, confirm with local institution rules.