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

  1. Select your last period start date
  2. Enter your average cycle length (typically 21-35 days)
  3. Click calculate
  4. View your ovulation date and fertile window
  5. 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

How accurate is ovulation calculation?

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.

What if my cycle is irregular?

Record your cycles for the last 6 months and use the average. If cycles vary by more than 7 days, consult a gynecologist.

Can I only get pregnant during the fertile window?

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.

This calculator is for reference only and does not replace medical advice. Consult a gynecologist for accurate diagnosis.

📚 国別の計算ガイド

計算ロジック

金融・ローン・比率・単位変換の公開標準を使用します。

参照範囲

公開された基準と各国で一般的な運用慣行を参照します。

前提条件

税率・手数料・上限は地域や金融機関で異なります。

結果の読み方

結果は基準シナリオとして活用してください。最終判断前に金融機関見積と税務条件を比較してください。

ロケール既定値

通貨: JPY

単位: metric

税計算モデル: US payroll estimate

法規上の注意

本ツールは国別プリセットによる概算です。実際の契約条件や法的上限は金融機関・地域法令により異なる場合があります。

推奨アクション

  • 申込前に最低2〜3社の条件を比較してください。
  • 手数料・税務・繰上返済条項を書面で再確認してください。
  • 金利+1〜2%と収入減少のストレスケースも確認してください。

実際の契約前に、必ず現地機関の最新条件を確認してください。

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