Calculadora de Fecha de Parto

The pregnancy due date calculator uses Naegele's Rule — the medically established method for estimating the expected delivery date. The formula takes the first day of your Last Menstrual Period (LMP), adds 280 days (40 weeks), and adjusts by the difference between your actual cycle length and the standard 28 days. This gives a personalised estimate that accounts for natural variation in menstrual cycles. The result — alongside your current week of pregnancy, trimester, and a visual progress bar — gives you the complete picture of your pregnancy timeline at a glance.

Our calculator also shows you four key milestones: Week 12 (when the heartbeat becomes detectable by Doppler), Week 20 (the anatomy scan), Week 28 (the start of the third trimester), and Week 37 (full term). These are the landmarks your healthcare provider will likely discuss with you at each prenatal appointment. For tracking the days and weeks of your pregnancy, our Date Calculator and Countdown Timer are perfect companion tools.

Important: The estimated due date is exactly that — an estimate. Only about 5% of babies are born on their exact due date. A range of plus or minus two weeks around the due date is entirely normal. Always rely on your doctor or midwife for medical guidance, particularly if your cycle length varies significantly or if you have any pregnancy complications.