Created By : Vaibhavi Kumari

Reviewed By : Phani Ponnapalli

Last Updated : Apr 20, 2023

This free tool Pregnancy Due Date Calculator estimates your baby's due date and shows how many weeks pregnant you are to date. You need to enter the all values in the specified box and press the calculate button to get the exact answer you need.

Calculation method:
First day of your last period:
Cycle Length:

Due Date Calculator Contains Total 4 Parts

There are different ways to find out the number of weeks pregnant you are, here are the methods the due date pregnancy calculator use.

1. Due Date Based On Last Period

To calculate the due date based on the last period, add 40 weeks or 280 days from your last period. There will be a few days' difference based on your cycle length which we factor into the due date calculation. If you are unsure about your cycle length, select the not sure option.

For Example: When will my baby be born using the method last period and the date of the last period is 2nd February 2023 with a cycle length of 30 days?

Given that,

Method = Last Period

First Day of the last period = 2nd February 2023

Cycle Length = 30 days

So, in the Last Period method,

Due Date = First Day + (280 + cycle - 28) days

Due Date = (2nd February 2023) + (280 + 30 days - 28) days

Then the Due Date is Sunday, November 19, 2023

*Note if the cycle length is Not Sure, the cycle is 0.

2. Due Date Based On Conception Date

To calculate the due date based on your conception date, add 266 days to your conception date to get an estimate due date.

For Example: When will my baby be born using the method conception date and the date of conception is 31st March 2023?

Given that,

Method = Conception Date

Date of Conception = 31st March 2023

So, in the Conception Date method,

Due Date = Conception Date + 266 days

Due Date = (31st March 2023) + 266 days

Then the Due Date is Friday, December 22, 2023.

3. Due Date Based On IVF Method 

To calculate using IVF, count out to 38 weeks or 266 days. Then subtract 3 or 5 days depending on your selection of IVF 3 or 5-day transfer date.

For Example: When will my baby be born using the method IVF and the date of transfer are 13th July 2023 with IVF 3 Day Transfer Date?

Given that,

Method = IVF Method

Date of Transfer = 13th July 2023

IVF method type = IVF 3 method

So, in the IVF method,

Due Date = Date Transfer + 266 - IVF Method days

Due Date = (13th July 2023) + 266 - 3

Then the Due Date is Monday, April 01, 2024.

4. Due Date Based On Ultrasound Method 

To calculate the due date based on ultrasound, Count out to 40 weeks or 280 days, and then subtract the gestational age.

For Example: When will my baby be born using the method of Ultrasound, the date of ultrasound is 19th August 2023 with the number of weeks 15 and days 6?

Given that,

Method = Ultrasound Method

Date of Ultrasound = 19th August 2023

Weeks = 15

Days = 6

So, with Ultrasound Method,

Due Date = Date of Ultra Sound + (280 - total no of days from )

Then the Due Date is Sunday, February 04, 2024.

FAQs On Due Date Calculator

1. What is the fastest way to convert the due date calculator?

The fastest way to convert due dates is by using our handy free tool i.e. Due Date Calculator.

2. How many weeks in total for pregnancy?

The total number of weeks during pregnancy is 40 weeks and the days are 280 days.

3. Is it alright to deliver the baby in the 42nd week?

If you go over 42 weeks pregnant, there is a high risk of stillbirth, although most babies remain healthy.