Due Date Calculator: Calculate Your Baby's Estimated Delivery Date

Use the Naegele method to calculate your baby's estimated delivery date based on your Last Menstrual Period (LMP) or conception date.

Input Parameters

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Fill in the required parameters on the left and click calculate to see the detailed results and analysis.

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Preparing for Delivery Day with the Due Date Calculator

Knowing your baby's birth date is not just about counting down the days, but also about preparing mentally, financially, and physically to welcome a new family member. The Estimated Due Date (EDD) is the primary benchmark for doctors and midwives to monitor your pregnancy's progress.

Various Ways to Calculate the Due Date

There are several methods used to predict the date of delivery:

  • 1Based on LMP (Last Menstrual Period): This is the most commonly used method (Naegele's Rule). The calculator adds 40 weeks or 280 days from the first day of your last period.
  • 2Based on Conception Date: If you know when conception occurred, the due date is calculated by adding 266 days from that date.
  • 3Based on Ultrasound (USG): Often considered the most accurate in the first trimester because the doctor directly measures the fetus's length (Crown-Rump Length). The ultrasound due date might differ slightly from the LMP version.

    • Understanding Pregnancy Terms

  • •Preterm: Born before 37 weeks of pregnancy.
  • •Full-term (Aterm): Born within the range of 37 - 42 weeks. Most healthy deliveries occur in this range.
  • •Post-term: Born after 42 weeks of pregnancy, which usually requires medical induction.

    • What to Prepare Before Your Due Date?

  • •Maternity Leave: Ensure you have arranged your leave schedule at least 2-4 weeks before your due date.
  • •Hospital Bag: Pack baby clothes, blankets, identification documents, and essentials for the mother in one easy-to-carry bag.
  • •Choosing a Health Facility: Decide whether you will deliver at a hospital, birth center, or with a home birth plan.
  • •Birth Plan: Discuss delivery methods (vaginal or c-section) and your partner's support in the delivery room.

    • Factors Affecting the Actual Birth Date

    It is very rare for a baby to be born exactly on their due date. Several factors influencing this include:

  • •Pregnancy Status: First-time pregnancies tend to go past the due date more often.
  • •Family History: Genetic factors from the mother can influence the length of the pregnancy.
  • •Medical Conditions: Complications like gestational diabetes or hypertension can trigger earlier delivery.

    • ? Frequently Asked Questions

    Q What percentage of babies are born exactly on their due date?

    Only about 4% to 5% of babies are born exactly on their estimated due date. The EDD is just an estimate to monitor fetal development, not a fixed appointment date.

    Q What if I forget the date of my last period (LMP)?

    If you forget, your doctor will usually perform an early ultrasound (first trimester) to measure the fetus and provide a fairly accurate due date estimate.

    Q Why does the ultrasound due date often change?

    An ultrasound measures the physical size of the fetus. Fetal growth can be slightly faster or slower at certain times, so the machine might provide a shifted estimate date at each check-up.

    Q When should I worry if I haven't given birth after my due date?

    If you are more than one week past your due date (41st week), your doctor will usually perform close observation or suggest induction to avoid risks as the placenta begins to age and nutrition delivery decreases.

    Q Is the due date calculated using the Gregorian calendar?

    Yes, medical standard calculations use the Gregorian calendar with the assumption that the average human pregnancy length is 280 days from the last menstrual cycle.