Home
Back
EDD Expect Formula:
| From: | To: |
The What To Expect When Expecting Due Date Calculator estimates the expected delivery date (EDD) based on the last menstrual period (LMP) using the standard formula of LMP plus 280 days. This provides an accurate prediction of when to expect the baby's arrival.
The calculator uses the standard due date formula:
Where:
Explanation: This calculation is based on Naegele's rule, which assumes a 28-day menstrual cycle and ovulation occurring on day 14. The 280 days represent 40 weeks of gestation.
Details: Accurate due date calculation is crucial for proper prenatal care, monitoring fetal development, planning maternity leave, and preparing for delivery. It helps healthcare providers track pregnancy milestones and identify potential complications.
Tips: Enter the first day of your last menstrual period in the date field. Ensure the date is accurate for the most precise due date calculation. The calculator will automatically add 280 days to determine your estimated due date.
Q1: How Accurate Is This Due Date Calculation?
A: This method is approximately 80% accurate for women with regular 28-day cycles. Only about 5% of babies are born exactly on their due date.
Q2: What If My Cycle Is Not 28 Days?
A: For cycles longer or shorter than 28 days, adjustments may be needed. Consult with your healthcare provider for a more personalized due date calculation.
Q3: When Should I Confirm My Due Date With Ultrasound?
A: An early ultrasound (8-12 weeks) can provide the most accurate due date confirmation and is recommended for all pregnancies.
Q4: Can The Due Date Change During Pregnancy?
A: Yes, healthcare providers may adjust the due date based on ultrasound measurements, especially if there's a significant difference from the LMP-based calculation.
Q5: What Is The Normal Range For Delivery?
A: Full-term pregnancy is considered 37-42 weeks. Most deliveries occur between 38-41 weeks gestation.