New Design Not working For You?

If the new page layout is not working for you, please Contact Me and let me know what device, operating system, and web browser (with version numbers) you are using so I can attempt to get the layout working for your setup.

About the Redesign

If you visited this site prior to September 15th, 2018, you've no doubt noticed that I've since launched a complete redesign of the website.

If you're not happy with the new design, I sincerely apologize. I would have preferred to keep the old desktop design, but considering the majority of my site's users are now accessing the site from small-screen, touch-enabled, mobile devices, and considering Google is now penalizing websites for not being mobile/thumb friendly, I was left with no choice but to switch to a responsive, mobile-first design.

The good news is that now that I have combined the three separate versions of the site (mobile, desktop, and ad-free member) into a single design, this will free up a ton of my time for working to make the mobile-optimized calculators more desktop/laptop friendly. In fact, some of the redesigned calculators already offer a desktop-optimized form that becomes visible when you increase the width setting of the calculator (within the "Calculator Preferences" expandable panel).

Thank you in advance for your help and patience as I work to improve the redesign.

-Dan

Calculator Preferences
Reverse Due Date Calculator Sign

Reverse Due Date Calculator

This extremely popular conception date calculator will calculate what date and day of the week your baby was conceived on based on your pregnancy due date. Also includes estimated dates for the missed menstrual period and for the range of days the pregnancy-causing "event" likely occurred within. Plus, you can also select any birth date -- meaning you can calculate conception dates for yourself and others.

Learn More

Selected Data Record:

A Data Record is a set of calculator entries that are stored in your web browser's Local Storage. If a Data Record is currently selected in the "Data" tab, this line will list the name you gave to that data record. If no data record is selected, or you have no entries stored for this calculator, the line will display "None".

DataData recordData recordSelected data record: None
Month:Birth month:Month of birth:Pregnancy due month (or birth month):

Pregnancy due month:

Select the month of your baby's birth due date. Note that you can also select any date of birth to calculate when you or someone else was most likely conceived.

Day:Birth day:Day of due date:Pregnancy due day (or birth day):

Pregnancy due day:

Select the day of the month of your baby's birth due date. Note that you can also select any date of birth to calculate when you or someone else was most likely conceived.

Year:Birth year:Year of due date:Pregnancy due year (or birth year):

Pregnancy due year:

Select the year of your baby's birth due date. Note that you can also select any date of birth to calculate when you or someone else was most likely conceived.

Date:Conceive date:Conception date:Estimated date of conception:

Conception date:

This is 266 days subtracted from the selected pregnancy due date (the average per Naegele's Rule).

Period:Last period:Last period date:Estimated last period date:

Last period date:

This is 14 days prior to the conception date (assuming ovulation occurred on day 14 of your menstrual cycle).

If you would like to save the current entries to the secure database, tap or click on the Data tab, select "New Data Record", give the data record a name, then tap or click the Save button. To save changes to previously saved entries, simply tap the Save button. Please select and "Clear" any data records you no longer need.

Feedback AppreciatedFeedback Greatly AppreciatedYour Feedback Would Be Greatly AppreciatedYour Feedback Is Greatly Appreciated
Heading

Tip

Get the App!

$0.99, iPhone or Android.

iPhoneAndroid
iTunes store iconGoogle Play store icon
QR Code for Conception Date Calculator App
Help and Tools

Help and Tools:

This section, which you can Unstick or Hide in the Calculator Preferences (just above the top of the calculator), contains the following tabs (content too long to fit within bordered frame can be scrolled up and down):

About: Click this tab for an introduction to the calculator.

Instructions: Click this tab for step-by-step instructions for using the calculator.

Terms: Click this tab for a list of the descriptions that are located within each popup help button (info icons).

PCalc: Click this tab for a handy "pocket" calculator you can use when you need to calculate an entry needed for the calculator.

Data: Click this tab to save a set of entries or a note in between visits. Entries and notes will be stored to your web browser's local storage (if supported by your browser of choice), meaning they can only be recalled with the same device and web browser you were using when you saved them. If you'd like to save entries and notes between devices you can do so by subscribing to the Ad-Free Member Version.

 

Favorites

Add or remove this page to/from my favorites.