Pregnancy Due Date Calculator
Calculate your estimated due date and see important pregnancy milestones.
days
Standard cycle is 28 days. Adjust if your cycle is different.
Understanding Pregnancy Due Dates
A pregnancy typically lasts about 40 weeks from the first day of the last menstrual period (LMP), or about 38 weeks from conception. Only about 4-5% of babies are born on their exact due date.
Calculation Methods
- LMP Method: Adds 280 days to the first day of your last period. Adjusts for cycle length variations.
- Conception Date: Adds 266 days (38 weeks) to the date of conception.
- IVF 3-Day Transfer: Adds 263 days to the transfer date (accounts for 3-day embryo development).
- IVF 5-Day Transfer: Adds 261 days to the transfer date (accounts for 5-day blastocyst development).
Pregnancy Trimesters
- First Trimester (Weeks 1-12): Early development, organ formation, morning sickness common.
- Second Trimester (Weeks 13-27): Often called the "honeymoon phase," baby movement felt.
- Third Trimester (Weeks 28-40): Rapid growth, preparing for delivery.
Naegele's Rule (LMP Method):
Due Date = LMP + 280 days + (Cycle Length - 28 days)
Due Date = LMP + 280 days + (Cycle Length - 28 days)
Note: This calculator provides estimates only. Ultrasound dating, especially in the first trimester, often provides more accurate due date predictions. Always consult with your healthcare provider for personalized prenatal care.