Due Date Calculator
Calculate your baby's due date based on last menstrual period or conception date
About this calculator
The Due Date Calculator helps expectant parents estimate when their baby will arrive by calculating the expected delivery date based on either the last menstrual period (LMP) or conception date. This essential pregnancy tool uses the standard 280-day gestation period to provide an accurate due date estimate, helping you plan and prepare for your baby's arrival. Healthcare providers commonly use this same calculation method to track pregnancy milestones and schedule important prenatal appointments.
How to use
Enter either your last menstrual period start date or your conception date into the calculator. Select which date type you're using from the dropdown menu. Click calculate to instantly receive your estimated due date along with current pregnancy week and trimester information.
Frequently asked questions
How accurate are due date calculations?
Due dates are estimates with about 5% of babies born on their exact due date. Most babies arrive within two weeks before or after the calculated date.
Which method is more accurate - LMP or conception date?
Conception date is typically more accurate if you know the exact date, while LMP is more commonly used and reliable for most women.
Can my due date change during pregnancy?
Yes, healthcare providers may adjust your due date based on ultrasound measurements, especially early pregnancy scans which can be more precise than date calculations.