A few things to remember before you use this due date calculator. No method to determine your expected due date is 100% accurate. The most reliable method to arrive at this date is via measurements of the fetus, taken during your first ultrasound.
Keep in mind no one has shared this date with your baby so the baby can decide to arrive earlier or later, depending on their rate of development. This tool will merely give you a rough idea of when that could be, and can potentially be off by a week or two, either way.