Find out when your baby is due using your last period or conception date. Medically accurate, instant, and 100% private.
This calculator uses standard Naegele's Rule. The Ovuloom app uses AI that learns your unique cycle patterns for significantly more accurate predictions.
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Your estimated due date (EDD) is calculated using Naegele's Rule, the same method OB/GYNs use worldwide. It works by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP).
A full-term pregnancy typically lasts about 40 weeks from the first day of your last period. This includes roughly 2 weeks before ovulation actually occurs. From conception, pregnancy lasts about 266 days (38 weeks).
If your cycle is longer or shorter than 28 days, our calculator adjusts for this. For example, if your cycle is 35 days, you likely ovulated around day 21 (not day 14), so your due date shifts forward by 7 days.
For IVF pregnancies, the due date is calculated from the embryo transfer date. For a Day 5 (blastocyst) transfer, we add 261 days. For a Day 3 transfer, we add 263 days. This is more precise than LMP-based calculations because the exact fertilization timing is known.
Remember: only about 5% of babies arrive on their exact due date. Most are born within a 2-week window around the EDD. For the most accurate tracking, download the Ovuloom app for AI-powered week-by-week updates personalized to your pregnancy.
Your due date is calculated using Naegele's Rule: add 280 days (40 weeks) to the first day of your last menstrual period. If you enter a conception date, we add 266 days (38 weeks). This is the same method used by OB/GYNs worldwide.
Only about 5% of babies are born on their exact due date. Most babies arrive within 2 weeks before or after. Naegele's Rule assumes a 28-day cycle. The Ovuloom app uses AI to adjust predictions based on your unique cycle data for better accuracy.
Use the Conception Date method if you know roughly when you conceived. If you don't know either date, an early ultrasound (before 12 weeks) is the most accurate way to determine your due date. The Ovuloom app helps you track cycles so you always have this data.
First Trimester (Weeks 1-12): Organ development, morning sickness common. Second Trimester (Weeks 13-26): Baby grows rapidly, you may feel movement around week 18-20. Third Trimester (Weeks 27-40): Baby gains weight and prepares for birth.
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