1. What is the BabyCenter Due Date Calculator?

The BabyCenter Due Date Calculator estimates your pregnancy due date by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP). This is based on the standard Naegele's rule adjusted for modern pregnancy dating.

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 pregnancy (40 weeks)

Explanation: Pregnancy is typically calculated from the first day of your last period because most women don't know exactly when they ovulated, but they usually remember when their last period started.

3. Importance of Due Date Calculation

Details: Knowing your estimated due date helps healthcare providers monitor fetal development, schedule important prenatal tests at the right times, and determine if the pregnancy is progressing normally.

4. Using the Calculator

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

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.

Q2: What if I know my conception date?
A: If you know your conception date, you can calculate by adding 266 days (38 weeks) to that date.

Q3: What if my cycles aren't 28 days?
A: The calculation assumes a 28-day cycle with ovulation on day 14. If your cycles are longer/shorter, your due date may need adjustment.

Q4: Will my doctor use this same calculation?
A: Doctors typically use this method initially but may adjust based on early ultrasound measurements.

Q5: When should I contact my healthcare provider?
A: Contact them as soon as you think you're pregnant to begin prenatal care, regardless of the calculated due date.