Question 1

How is my due date calculated?

Accepted Answer

Your due date is calculated by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP). This is called Naegele's rule. If you know your conception date, we add 266 days (38 weeks) instead. Only about 5% of babies are born on their exact due date - most arrive within 2 weeks before or after.

Question 2

How accurate is a due date calculator?

Accepted Answer

Due date calculators are estimates based on average pregnancy length. Only 4-5% of babies arrive on their exact due date. About 80% of babies are born within 2 weeks of their due date (between 38-42 weeks). Your doctor may adjust your due date based on ultrasound measurements, especially in the first trimester which is most accurate.

Question 3

What is the most accurate way to determine my due date?

Accepted Answer

The most accurate due date comes from a first-trimester ultrasound (before 14 weeks), which is accurate within 5-7 days. LMP-based calculations assume a 28-day cycle and ovulation on day 14, which varies between women. If your cycles are irregular or you're unsure of your LMP, an early ultrasound is recommended.

Pregnancy Due Date Calculator

Pregnancy Progress

📅 Key Milestones

📧 Get Weekly Pregnancy Updates

Pregnancy Progress

📅 Key Milestones

Share Your Due Date

📧 Get Weekly Pregnancy Updates