1. What is the Due Date Calculator?

The Due Date Calculator estimates the expected delivery date of a pregnancy based on the last menstrual period (LMP). The calculation follows 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 duration of pregnancy (40 weeks)

Explanation: This calculation assumes a regular 28-day menstrual cycle with ovulation occurring on day 14. The actual delivery date may vary by ±2 weeks.

3. Importance of Due Date Calculation

Details: Accurate due date estimation is crucial for proper prenatal care, monitoring fetal development, and determining the appropriate timing for various prenatal tests and interventions.

4. Using the Calculator

Tips: Enter the first day of your last menstrual period in the date field. The calculator will display your estimated due date and current gestational age.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this 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 my cycles aren't 28 days long?
A: For irregular cycles or cycles longer/shorter than 28 days, the calculation may need adjustment. Consult your healthcare provider.

Q3: When is the due date typically confirmed?
A: An early ultrasound (first trimester) can provide the most accurate due date estimation.

Q4: Does this work for IVF pregnancies?
A: For IVF pregnancies, the calculation is based on the embryo transfer date, not LMP.

Q5: Why is 280 days used?
A: This represents 40 weeks from LMP, accounting for the typical 2 weeks between LMP and conception in a 28-day cycle.