Overview
What Is a Due Date Calculator?
This tool estimates your due date using Naegele's Rule, which adds 280 days (40 weeks) to the first day of your last menstrual period.
Estimate your due date instantly.
This tool estimates your due date using Naegele's Rule, which adds 280 days (40 weeks) to the first day of your last menstrual period.
Useful for early pregnancy planning, though your healthcare provider's estimate based on ultrasound is more precise.
Input the date your last menstrual period began.
The result updates automatically.
Using Naegele's Rule: adding 280 days (40 weeks) to the first day of your last menstrual period.
It's a standard estimation method, though actual delivery dates vary - your healthcare provider's ultrasound dating is typically more precise.
This calculator assumes a standard 28-day cycle - irregular cycles may make this estimate less accurate; consult your doctor for a more personalized estimate.
Full term is typically considered 37-42 weeks, with babies born anytime in this range considered full term.
No, this is an informational estimate only - always follow your healthcare provider's guidance for prenatal care.
Only about 5% of babies are born exactly on their calculated due date - it's an estimate, not a guarantee.
Yes, though this calculator uses last menstrual period, which is the standard clinical dating method.
No, calculations happen entirely in your browser.
No, this calculates a standard single-pregnancy estimate - multiple pregnancies often have different timelines.
Yes, completely free with no sign-up required.