预产期计算器
输入末次月经或受孕日期，精准计算宝宝到来时间
输入末次月经或受孕日期，精准计算宝宝到来时间
医学上普遍采用Naegele 法则来推算预产期：从末次月经第一天（LMP）算起，月份减 3 或加 9，日期加 7，大致得出 40 周后的预产期。更精确的算法是 LMP 日期加上 280 天。如果已知受孕日期，则加 266 天。
示例：末次月经为 2026 年 1 月 1 日，加 280 天后预产期为 2026 年 10 月 8 日。若已知受孕日为 2026 年 1 月 14 日，加 266 天同样得到 10 月 8 日。
但只有约 5% 的宝宝会在预产期当天出生，绝大多数在预产期前后两周内降临。本工具提供基于标准孕周的参考值，请务必遵医嘱定期产检。
如果周期较长或较短，Naegele 法可能不准确。医生通常会通过早期 B 超（孕 6-8 周）测量胎囊和胎芽大小来校正预产期。
排卵和受孕可能晚于或早于标准 28 天周期的第 14 天。B 超测量胎儿大小可以更准确地修正，最终以医生判断为准。
预产期超过 1 周（41 周）仍无产兆，医生会加强监护，必要时进行催产。不要过度焦虑，听从专业指导。
Enter your LMP or conception date to estimate your baby's arrival
The standard method is Naegele's Rule: add 280 days (40 weeks) to the first day of your last menstrual period (LMP). If you know your conception date, add 266 days. This calculator provides a close estimate used in prenatal care.
Example: LMP January 1, 2026 → Due Date October 8, 2026. Conception January 14, 2026 → Due Date October 8, 2026 (same result).
Only about 5% of babies arrive exactly on their due date. Most births occur within two weeks before or after. Always consult your healthcare provider for a personalized plan.
If your cycle is longer or shorter than 28 days, the LMP method may be inaccurate. An early ultrasound (6‑8 weeks) is the most reliable way to date a pregnancy.
Ovulation and conception don't always occur on day 14. Ultrasound measurements of the fetus provide a more precise estimate, which your doctor will use.
If you reach 41 weeks without labor, your provider will increase monitoring and may discuss induction. Try to stay calm and follow medical advice.