Estimate your baby's due date and see how far along you are.
This calculator uses Naegele's Rule, the standard method used by obstetricians: add 280 days (40 weeks) to the first day of your last menstrual period, then adjust for cycle length. If your cycle is longer or shorter than 28 days, the due date shifts accordingly.
Keep in mind that only about 5% of babies are born on their actual due date. Most arrive within two weeks before or after. Your healthcare provider may adjust the date based on ultrasound measurements, especially if they differ significantly from the LMP-based estimate.