How to Calculate Your Due Date

How to Calculate Your Due Date

Congratulations on your pregnancy!

Early pregnancy can be an overwhelming time, and your head may feel busy with a mix of emotions, questions and worries. One of the first things you’re probably desperate to know is your due date. So, while I can’t help you with the morning sickness, or the sleepless nights worrying about whether you’re ready to be a mum, or the almost obsessive urge to blurt out the news to everyone you meet, I can help with your due date.

How to calculate your due date – if you want to calculate it yourself, other than using our Application.

It is important to note that this method is more effective for women with regular 28 day cycles. If you have an irregular cycle, the date given by this method will be less reliable.

  1. Determine the first date of your last menstrual period. If you keep note of your cycle, or use a smartphone app to keep track of it, this will be easy enough. If you don’t keep records of your periods, try to remember events around your last cycle. For example, did you stay at a friends, or go swimming? Information like this may help to remind you of the timing of your last cycle.
  2. Add 40 weeks to the date above (280 days). This is your calculated due date.

Don’t permanent marker that date into your diary just yet though, remember this is just an educated guess. The calculated due date is used as a rough estimate to ensure the dating scan is scheduled in the correct window. Dating scans are most reliable when they occur between the eleventh and thirteenth week of pregnancy, which is why your date scan usually happens around week 12. By calculating your due date using the above method, your doctor can book your dating scan correctly and give you the best chance at an accurate due date.

You should bear in mind, however, that only five percent of babies are born on their due dates. Unfortunately, without access to your diary, Junior won’t know when he’s expected to make his grand entrance. Try not to get fixated on your due date, because you may end up disappointed when the day passes without incident.

You may even like to keep your due date relatively private, only telling close friends and family. The due date is bad enough when you spend it grumpily bouncing on a birthing ball while eating a vindaloo and staring at the clock. It’s made a whole lot worse when you start getting text message from colleagues, old friends and people you barely know asking if the baby is here yet.

Written by Fiona, proud owner of a toddler, @fiona_peacock

This information is not intended to replace the advice of a trained medical doctor. Health & Parenting Ltd disclaims any liability for the decisions you make based on this information, which is provided to you on a general information basis only and not as a substitute for personalized medical advice. All contents copyright © Health & Parenting Ltd 2017. All rights reserved.