Due Date Calculator
Calculate your due date from Last Menstrual Period (LMP) or conception date using Naegele's rule.
How to Use the Due Date Calculator
Calculate your due date from Last Menstrual Period (LMP) or conception date using Naegele's rule. Enter your information in the form above and get instant results.
Medical Disclaimer: This tool is for informational purposes only. Always consult your healthcare provider for medical advice.
Frequently Asked Questions
How is due date calculated?
Using Naegele's rule: LMP + 280 days (40 weeks). From conception date we add 266 days (38 weeks).
How accurate is the due date?
Only about 5% of babies are born on their exact due date. The due date is an estimate — most births occur within 2 weeks before or after.
What is LMP?
LMP stands for Last Menstrual Period. It is the first day of your last period before pregnancy.