Pregnancy Due Date Calculator Guide

One of the first questions every expectant mother asks is: "When is my baby due?" A pregnancy due date calculator helps you estimate your delivery date based on your last menstrual period (LMP), conception date, ultrasound, or IVF transfer. Understanding how due dates work can help you plan your pregnancy journey with confidence.

How Due Dates Are Calculated

Healthcare providers use several methods to calculate your estimated due date (EDD). The most common method is Naegele's rule, which adds 280 days (40 weeks) to the first day of your last menstrual period. This assumes a regular 28-day cycle with ovulation on day 14.

Methods of Calculating Due Date

• Last Menstrual Period (LMP): Add 280 days to the first day of your last period. Most accurate with regular cycles.
• Conception Date: Add 266 days to the date of conception. More accurate if you tracked ovulation.
• Ultrasound Dating: Most accurate in the first trimester (within ±5 days). Measures crown-rump length.
• IVF Transfer Date: Most precise — exact date of embryo transfer is known.

How Accurate Is Your Due Date?

Only about 5% of babies are born on their exact due date. Most arrive within a 2-week window (37-42 weeks). Your due date is an estimate, not a deadline. Early ultrasounds are more accurate than LMP calculations, especially if your cycles are irregular.

What to Do After Calculating Your Due Date

Once you know your due date, you can plan your antenatal care schedule, track your pregnancy week by week, and prepare for your baby's arrival. The Nurtura360™ kit includes a pregnancy journal and appointment tracker to help you stay organized throughout your journey.