Pregnancy Due Date Calculator - eDaily Tech

Pregnancy Calculator

Date of Last Menstrual Period:

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Due Date, Conception Date Calculation Results:

Estimated Fertility Dates :

to

Estimated Conception Date :

First Trimester Ends(12 Weeks) :

Second Trimester Ends(27 Weeks):

Estimated Due Date(40 Weeks) :

How do you calculate your expected delivery date?

Follow the steps below to calculate your expected delivery date.

Using your last menstrual period as a guide:

Pregnancies typically last 40 weeks or 280 days from the LMP (last menstrual period), with only 4% of babies born on the expected delivery date. After 37 weeks of pregnancy, a woman may go into labor at any time.

You can use the following methods if you have a regular 28-day menstrual cycle:

To calculate your expected delivery date, use Naegele's rule:

Subtract three months from the first day of your last menstrual cycle plus seven days.

— The Naegele rule

For example, if your LMP is on October 1st, 2022, you must add 7 days to Oct 1st, which is Oct 8th, and then subtract 3 months, which is July 8th, 2023.

Using the conception date: If you know the ovulation day by tracking ovulation symptoms or ovulation test strips, you can multiply it by 266 to get the expected delivery date.

When your periods are irregular, we must rely on an ultrasound to determine the gestational age and due date. During the ultrasound, we measure the fetus's crown-rump length and calculate the gestational age.

The results will be accurate during the first trimester. The early scan is known as the dating scan, and it is the most reliable for calculating the expected delivery date.

The dating scan calculated during the second trimester will be off by about two weeks. There will be a nearly three-week gap during the third trimester. The third-trimester scan is not used to determine the pregnancy's age.

How do you calculate your due date if you don't know when your last menstrual period was?

An early ultrasound can determine the gestational age of the fetus, from which we can calculate the due date.

How do you figure out your due date if your menstrual cycle is irregular?

Some women's menstrual cycles are irregular and have longer cycles, such as a 35-day cycle. In these cases, some calculations must be performed to estimate the expected delivery date. Remember that the second half of a woman's menstrual cycle lasts 14 days, beginning with ovulation and ending with the next menstrual cycle.

For example, if your cycle is 35 days, you must have ovulated on day 21. Once you know when you ovulated, you can use the calculator to calculate the due date using adjusted LMP.