1. What is Due Date Reverse Calculation?

The Due Date Reverse Calculator estimates the conception date by subtracting 266 days from the estimated due date (EDD). This calculation helps determine the likely date of conception based on the expected delivery date.

2. How Does the Calculator Work?

The calculator uses the following formula:

Where:

• \( EDD \) — Estimated Due Date (date)
• \( 266 days \) — Standard gestation period from conception to due date

Explanation: This calculation assumes a standard 266-day gestation period from conception to estimated due date, which corresponds to approximately 38 weeks of gestation.

3. Importance of Conception Date Calculation

Details: Knowing the conception date is important for accurate pregnancy dating, understanding fetal development timelines, and for medical and personal record-keeping purposes.

4. Using the Calculator

Tips: Enter the estimated due date in the date field. The calculator will automatically compute and display the estimated conception date 266 days prior to the entered due date.

5. Frequently Asked Questions (FAQ)

Q1: Why 266 days specifically?
A: 266 days represents the average gestation period from conception to due date, which is approximately 38 weeks or 9.5 months.

Q2: How accurate is this calculation?
A: This provides an estimate based on average gestation periods. Actual conception dates may vary depending on individual factors and cycle regularity.

Q3: What's the difference between LMP and conception date?
A: LMP (Last Menstrual Period) is typically about 2 weeks before conception, so conception date calculations differ from LMP-based calculations.

Q4: Can this be used for pregnancy confirmation?
A: This is an estimation tool and should not replace medical confirmation of pregnancy or professional obstetric dating.

Q5: What if my due date was calculated differently?
A: Different methods (LMP, ultrasound) may yield slightly different due dates, which will affect the reverse calculation result.