出産予定日計算機
赤ちゃんの生まれる日を推定。
結果
推定出産予定日
--
How Due Date is Calculated
The due date is calculated by adding 280 days (40 weeks) to the first day of your last menstrual period. This assumes a regular 28-day cycle with ovulation occurring on day 14.
If you know your conception date, you can add 266 days (38 weeks) instead, which is the average length of pregnancy from conception.
Frequently Asked Questions
How accurate is the due date?
Only about 5% of babies are born on their exact due date. Most babies arrive within 2 weeks before or after the estimated date, which is completely normal.
What if I have an irregular cycle?
If your cycle is longer or shorter than 28 days, your healthcare provider may adjust your due date. Ultrasound measurements in the first trimester can also help refine the estimate.
When should I see a doctor?
You should schedule your first prenatal appointment as soon as you know you are pregnant, typically around 8 weeks after your last menstrual period.