Pregnancy Due Date Calculator | Conception or Last Period
Pregnancy Due Date Calculator
Calculate your estimated due date based on conception date or last menstrual period
Your Pregnancy Due Date
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Weeks Pregnant
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Days Remaining
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Frequently Asked Questions
Our calculator provides an estimate based on standard pregnancy calculations. Actual due dates may vary slightly based on individual factors. Most babies are born within two weeks before or after the estimated due date.
Calculating by last menstrual period (LMP) is the standard medical method, adding 280 days to the first day of your last period. Calculating by conception date adds 266 days (38 weeks) to the conception date. The LMP method is more commonly used and often more accurate.
If you don't know your last period date, the conception date method can provide an estimate. However, for the most accurate results, an ultrasound dating scan is recommended.
Understanding Your Pregnancy Due Date Calculation
A pregnancy due date calculator is an essential tool for expectant mothers to estimate when their baby will arrive. The most common method uses the first day of your last menstrual period (LMP) to calculate your estimated due date by adding 280 days (40 weeks). This calculation is known as Naegele's Rule and is the standard method used by healthcare professionals.
Alternatively, if you know your conception date, you can calculate your due date by adding 266 days (38 weeks) to that date. This method is less commonly used since many women don't know their exact conception date, but it can be useful if you've been tracking your ovulation or using fertility treatments.
Your due date is an estimate rather than an exact date - only about 5% of babies are born on their actual due date. Most births occur between 37 and 42 weeks of pregnancy. Our calculator also provides information about which trimester you're in, how many weeks pregnant you are, and how many days remain until your due date.
Remember that every pregnancy is unique, and your healthcare provider may adjust your due date based on early ultrasound measurements or other factors. This calculator provides a helpful starting point for understanding your pregnancy timeline.
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