Don't Retract Pack

Due Date Calculator

Due Date Calculator

It goes without saying that nothing brings more joy into our lives than new parenthood. But along with this joy it also brings feelings of anxiety, nervousness, unpredictability and wonder. Babies are extremely unpredictable. No amount of parenting books, magazines, google searches or elders’ advice can prepare you fully for this mammoth task ahead of you. However, some amount of strategic planning can help you and calm your nerves while you wait for your bundle of joy.

Once you get a positive pregnancy test, the next step is to get it confirmed from your ob-gyn with an ultrasound. The doctor will most probably also give you your due date at this appointment. This appointment is generally held between 10 to 14 weeks. While you wait for your first appointment you can use this easy pregnancy due date calculator to help you start planning –

How to use this due date calculator?

The link will take you to the due date calculator. It is extremely easy to use. It takes the date of the first day of your last period and the approximate length of your menstrual cycle as input and gives you the estimated due date (EDD) as output.

How do due date calculators work?

Many due date calculators are available online today. They use different principles to calculate your baby’s due date. They are based on the date of the last menstrual period (LMP).

The Naegele’s rule for determining your baby’s due date is most commonly used by due date calculators. A pregnancy lasts for roughly 40 weeks from the day of conception and this duration is called the gestation period. Naegele’s rule adds 40 x 7 = 280 days to the first day of your menstrual cycle, the result of which is your baby’s due date. Here it is assumed that a woman’s period cycle runs for 28 days approximately and ovulation occurs on the 14th day.

However, some women have a menstrual cycle longer or shorter than 28 days. The Mittendorf-Williams rule takes this deviation into consideration. This makes it a more accurate method of calculating the due date. It takes different factors like race, height, weight, maternal age and average luteal phase length (second half of menstrual cycle after the day of ovulation) into consideration. This makes the calculation way more complicated.

This due date calculator uses the Mittendorf-Williams rule and hence is more accurate than other calculators you find online.

How accurate are due date calculators?

The accuracy of a due date calculator depends on multiple factors. If the expectant mother has regular monthly periods, there is a very high chance of the due date being accurate. However, for women with irregular periods it is important to confirm/determine the due date by measuring the size of the fetus during the first ultrasound appointment. Another point to note is that only around 5-6% women deliver their babies on the due date. Hence, a due date calculator provides you with an approximate due date or a range of 4 weeks between 38 and 42 weeks of pregnancy. Only a pregnancy above 42 weeks is considered overdue.


In conclusion, we can say that due date calculators are helpful in providing the expectant couples with a general idea of when to expect the arrival of their baby. The first day of the last period and length of cycle play a role in determining the due date. The Mittendorf-Williams method calculates the due date more accurately than the Naegele method as it takes into consideration a cycle size below or above the average. This factor makes the due date calculator more accurate when compared to others found online.

No comments:

Post a Comment