1. What is a Due Date Calculator?

The Due Date Calculator estimates when a pregnant woman is likely to deliver her baby based on the date of her last menstrual period (LMP). This calculation uses Naegele's rule, which adds 280 days (40 weeks) to the first day of the LMP.

2. How Does the Calculator Work?

The calculator uses the standard pregnancy calculation:

Where:

• LMP — First day of last menstrual period
• 280 days — Standard length of human pregnancy (40 weeks)

Note: This assumes a regular 28-day menstrual cycle. Adjustments may be needed for irregular cycles.

3. Importance of Due Date Calculation

Details: Knowing the estimated due date helps healthcare providers monitor fetal development, schedule important prenatal tests, and prepare for delivery. It also helps identify preterm or post-term pregnancies.

4. Using the Calculator

Tips: Enter the first day of your last menstrual period in the format YYYY-MM-DD. The calculator will add 280 days (40 weeks) to estimate your due date.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is the due date calculation?
A: Only about 5% of women deliver on their exact due date. Most deliver within 2 weeks before or after the estimated date.

Q2: What if I don't know my LMP?
A: An ultrasound in early pregnancy can help estimate gestational age if LMP is unknown or cycles are irregular.

Q3: Does this work for IVF pregnancies?
A: For IVF, the due date is typically calculated from the embryo transfer date plus 266 days (or 263 days for day-5 embryos).

Q4: Why 280 days?
A: This accounts for the average 2 weeks from LMP to conception plus 38 weeks (266 days) of gestation.

Q5: Can my due date change?
A: Yes, early ultrasound measurements may lead to adjustments, especially if they differ significantly from LMP-based calculations.