Free Pregnancy Due Date Calculator – Estimate Your Baby's Arrival
A pregnancy due date calculator is one of the most useful tools for expecting parents. Based on well-established obstetric methods, it estimates when your baby is likely to arrive, helping you plan prenatal care, prepare your home, and organize your schedule around this life-changing event.
Our calculator uses Naegele's Rule, the standard method used by healthcare providers worldwide. When you enter the first day of your last menstrual period (LMP), the calculator adds 280 days (40 weeks) to estimate your due date. If you know your conception date, it adds 266 days (38 weeks) instead.
The tool also shows your current gestational week, which trimester you are in, a visual progress bar, and key milestone dates. The three trimesters divide pregnancy into roughly equal thirds: weeks 1-12 (first trimester), weeks 13-26 (second trimester), and weeks 27-40 (third trimester).
Please remember that only about 5% of babies are born on their exact due date. Most healthy pregnancies result in birth between 37 and 42 weeks. This calculator provides estimates for planning purposes — always consult your healthcare provider for personalized medical advice and to confirm your due date with ultrasound dating.