Pregnancy Due Date Calculator

Your due date is calculated using Naegele's rule, the standard method used by healthcare providers:

• Start with the first day of your last menstrual period (LMP)
• Add 280 days (40 weeks) for a standard 28-day cycle
• If your cycle is longer or shorter than 28 days, the calculation adjusts accordingly
• Conception typically occurs around day 14 of your cycle (about 2 weeks after LMP)

Due date calculations provide an estimate, not an exact delivery date:

• Only about 5% of babies are born on their exact due date
• Most babies are born within 2 weeks before or after the due date
• Full-term pregnancy ranges from 37 to 42 weeks
• An early ultrasound (before 12 weeks) can provide a more accurate estimate
• Your healthcare provider may adjust your due date based on ultrasound measurements

If you have irregular periods, the LMP-based calculation may be less accurate:

• Try to estimate your average cycle length if possible
• An early ultrasound is recommended for more accurate dating
• Your doctor can measure the baby's size to estimate gestational age
• IVF pregnancies use the egg retrieval or embryo transfer date instead
• Discuss your cycle history with your healthcare provider

Pregnancy is divided into three trimesters, each with distinct developmental stages:

• First Trimester (Weeks 1-12): Major organs and body systems begin forming. Common symptoms include morning sickness and fatigue.
• Second Trimester (Weeks 13-26): Often called the "honeymoon phase." Baby's movements become noticeable, and many early symptoms subside.
• Third Trimester (Weeks 27-40): Baby gains weight rapidly and prepares for birth. Mom may experience increased discomfort as the baby grows.