Due Date Calculator

Due Date Calculator Tool

What an exciting time in your life – there’s another life coming into yours! We know that there are oh so many anxiety ridden activities in your life right now and calculating your due date, well that shouldn’t be one of them. Calculating dates is always a painful situation – especially with rolling dates within different months. That’s why we made it so light, easy, and fast to use! If you like that – you’ll like our other health and fitness calculators .

Due Date Calculator – Hustory & Background



The due date calculator and fertility window measurements are vital tools used in maternity healthcare. Rooted deep in history, this practice improves the possibility of conceiving and ensures a pregnancy follows a typical gestation period. In this article, we take a deep look at the history of these measurements, the link between them, their significance, and some fun facts surrounding due dates and fertility windows.

Quick Summary

  • The article explores the historical basis for measuring due dates and fertility windows.
  • It explains the relationship between the estimated due date and the fertility window.
  • We discuss the importance of understanding these measurements in everyday life.
  • The article addresses why one might want to calculate one’s due date.
  • Lastly, the article shares fascinating facts or trivia about measuring due dates and fertility windows.

History of Measuring Due Date

Historically, pregnancy duration calculations were based on observational evidence. Ancient Greeks adopted Hippocrates’ lunar-month concept, which stated that pregnancy lasts ten lunar months. However, modern measurements typically estimate the gestational period to be approximately 280 days or 40 weeks from the last menstrual period.

History of Measuring Fertility Window

Historically, women relied on physical signs to determine their fertility window. Clues such as changes in basal body temperature, cervical mucus, and menstrual cycle regularity helped women identify their most fertile days. Today, tools like ovulation predictor kits and fertility monitors provide more accuracy for those trying to conceive.

The Link Between Due Date and Fertility Window

Conception occurs within the fertility window of a woman’s menstrual cycle, which typically ranges from five days before ovulation to the day of ovulation. Thus, the estimated due date (EDD) is calculated from the first day of the last menstrual cycle, considering an average cycle length of 28 days and ovulation occurring on the 14th day.

Knowing your due date and fertility window is essential, regardless of whether you’re planning to conceive or are already pregnant. Understanding your menstrual cycle can aid in family planning and ensure optimal health for both mother and child by predicting important pregnancy milestones.

Common Reasons to Calculate Your Due Date

  • To plan maternity leave or arrange for child care.
  • To monitor fetal development stages.
  • To schedule medical appointments and tests.
  • To prepare mentally and emotionally for childbirth.

Do You Know?

  1. The earliest known pregnancy test dates back to 1350 BC in ancient Egypt.
  2. The risk of miscarriage is most significant during the first trimester.
  3. The average menstrual cycle for women aged 20-45 is 28 days, but it can range from 21-35 days.
  4. Research shows that only about 4% of babies are born exactly on their due date.
  5. Your fertility window typically falls in the middle of your menstrual cycle.
  6. Many other factors, including stress and diet, can affect your fertility window.
  7. The majority of newborns arrive between 37-40 weeks of gestation.
  8. Certain prenatal tests and screenings need to be performed during specific weeks of pregnancy.
  9. The term “due date” was first recorded in the late 1800s.
  10. The most common birth month in the US is September, hinting at high conception rates in December.

Remember, always contact your healthcare provider for personalized advice on calculating your due date and understanding your fertility window.

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    Here’s a tidbit. We include stats and interesting facts alongside of each of our calculators. These may be helpful to you along your way and provide you an insight and link to a resource to help you on your way.


    Chose not to be boring. We’ve found that a lot of our competitors (yes, there are online calculator competitors, can you believe the world we live in) have very BORING websites. We’re not trying to be boring. We want you to have a chuckle.