Estimate your due date and pregnancy timeline based on LMP or conception date.
Select a date to calculate results.
Results are estimates based on average cycle length. Actual delivery date may vary.
Estimate your due date and track your pregnancy progress with our free pregnancy calculator, based on your last menstrual period or conception date.
Using Naegele's Rule, the estimated due date is calculated as the first day of your last menstrual period, plus 280 days (40 weeks), the standard length of a full-term pregnancy.
It provides a standard estimate; only about 5% of babies are born exactly on their due date, most arrive within two weeks before or after.
Some versions let you input conception date directly, adding 266 days instead of using last menstrual period.
This calculator uses the standard 28-day cycle assumption; if your cycle is significantly different, your actual due date may vary.
No, always follow your healthcare provider's due date, which typically incorporates ultrasound measurements for greater accuracy.