1. What is the Due Date Calculation?

The due date calculation estimates the expected date of delivery based on the conception date. The standard calculation adds 266 days (38 weeks) to the conception date, representing the typical human gestation period.

2. How Does the Calculator Work?

The calculator uses the following formula:

Where:

• Conception Date — The date when fertilization occurred
• 266 days — The average length of human pregnancy from conception

Explanation: This calculation assumes a standard 38-week pregnancy from conception (rather than the more common 40-week estimate from last menstrual period).

3. Importance of Due Date Calculation

Details: Knowing the estimated due date helps in prenatal care planning, monitoring fetal development, and preparing for delivery. It's also important for determining if the pregnancy is progressing normally.

4. Using the Calculator

Tips: Enter the known or estimated conception date. The calculator will add 266 days to provide the estimated due date.

5. Frequently Asked Questions (FAQ)

Q1: Why 266 days instead of 280 days?
A: 280 days (40 weeks) is counted from the last menstrual period (LMP), while 266 days (38 weeks) is from conception, which typically occurs about 2 weeks after LMP.

Q2: How accurate is this calculation?
A: While 266 days is the average, normal pregnancies can vary by ±2 weeks. Only about 5% of women deliver on their exact due date.

Q3: What if I don't know my conception date?
A: If you know your last menstrual period, you can use an LMP-based calculator instead. Ultrasound dating in early pregnancy can also provide an estimate.

Q4: Does this work for IVF pregnancies?
A: Yes, for IVF pregnancies the conception date is known precisely, making this calculation particularly accurate.

Q5: Why might my doctor give a different due date?
A: Doctors may adjust the due date based on early ultrasound measurements or other clinical factors.