Due Date Parameters
28 Days
20 Days45 Days
Results are estimates. Not professional advice.
Understanding Your Due Date
Most pregnancies last around 40 weeks (or 280 days) from the first day of your last menstrual period (LMP). Our calculator uses Naegele's Rule, which is the standard medical method for estimating delivery dates.
Ovulation Window
Conception typically occurs 11-21 days after the first day of the last period.
Cycle Variance
Adjusting for your average cycle length provides a more accurate estimation.
It's important to remember that a due date is just an estimate. Only about 4% of babies are born on their actual due date. Most babies arrive between 37 and 42 weeks of pregnancy. Factors like your age, previous pregnancies, and maternal health can all influence the exact timing.
Frequently Asked Questions
How accurate is this due date calculator?
Our calculator is highly accurate based on the information provided. However, an early ultrasound (dating scan) performed by a healthcare professional is considered the most reliable way to determine a due date.
What if my cycle is irregular?
If your cycles are irregular, the LMP method might be less accurate. In these cases, doctors usually rely on physical exams and ultrasound measurements to estimate the age of the fetus.