1. What is the Pregnancy Due Date Calculator?

The Pregnancy Due Date Calculator estimates the expected delivery date based on the first day of your last menstrual period (LMP) using the standard UK calculation method (Naegele's rule adjusted for UK practice).

2. How Does the Calculator Work?

The calculator uses the standard UK calculation:

Where:

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

Explanation: This calculation assumes a regular 28-day menstrual cycle with ovulation occurring on day 14. The actual due date may vary based on individual cycle length and other factors.

3. Importance of Due Date Calculation

Details: Knowing your estimated due date helps with pregnancy planning, antenatal care scheduling, and monitoring fetal development. It's also used to determine gestational age for tests and screenings.

4. Using the Calculator

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

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 cycle isn't 28 days?
A: If your cycle is consistently longer or shorter, your midwife may adjust your due date accordingly, especially if confirmed by early ultrasound.

Q3: When will my NHS dating scan be?
A: In the UK, the NHS typically offers a dating scan between 8-14 weeks of pregnancy to confirm your due date.

Q4: Can the due date change?
A: Yes, your midwife may adjust your due date based on ultrasound measurements, especially if there's a significant difference from your LMP-based calculation.

Q5: What's the difference between due date and EDD?
A: They mean the same thing - EDD stands for Estimated Due Date, which is what this calculator provides.