EDD Calculator

Determines the estimated due date of birth based on menstrual cycle data.

Date of the cycle:
Menstrual cycle length:

AND by case

Choose a desired due date to see when to conceive:
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Steps on how to print your input & results:

1. Fill in the calculator/tool with your values and/or your answer choices and press Calculate.

2. Then you can click on the Print button to open a PDF in a separate window with the inputs and results. You can further save the PDF or print it.

Please note that once you have closed the PDF you need to click on the Calculate button before you try opening it again, otherwise the input and/or results may not appear in the pdf.

Information linked to the menstrual cycle days

The menstrual cycle data (i.e. the first day of the last menstrual cycle) and the cycle length (period) can offer useful information into the female’s reproductive health and pregnancy planning.

The menstrual cycle consists in a follicular phase, ovulation and a luteal phase.

The fertile window depends on egg and sperm viability and can range a few days before and after the ovulation, hence why it is during one of these days that conception (in case a pregnancy occurs) is considered to have taken place.

The estimated due date prediction is also linked to conception (approximately 266 days after conception) for a birth at 40 weeks.

Please note the statistics, however, as 50% of all women giving birth for the first time gave birth by 40 weeks and 5 days, while 75% gave birth by 41 weeks and 2 days. Meanwhile, 50% of all women who had given birth at least once before gave birth by 40 weeks and 3 days, while 75% gave birth by 41 weeks.

Also see below the percentage of babies born at each of the following weeks:

Week Percentage
35 1.4%
36 2.7%
37 6.3%
38 13.4%
39 26.4%
40 31.6%
41 16.2%
42 2%
43 0.1%

These percentages are based on stats from a sample of 11,771 babies born spontaneously, excluding the 3,652 babies who were induced.


Beckmann CRB. (2010) Obstetrics and Gynecology. Lippincott Williams & Wilkins. pp. 306–307.

Abman SH. (2011) Fetal and neonatal physiology (4th ed.) Philadelphia: Elsevier/Saunders.

Specialty: Obstetrics Gynecology

System: Reproductive

Article By: Denise Nedea

Published On: April 14, 2020

Last Checked: April 14, 2020

Next Review: April 14, 2025