Pregnancy Due Date Calculator

Congratulations on your pregnancy, you can use our pregnancy due date calculator to give you an approximate date for when your baby is due.

Version 0.1
Published on Monday 13 June 2022
Updated on Thursday 7 July 2022

Please be aware this calculator is in test mode and the content on this page is in the process of being expertly reviewed so please use with caution as the date and information provided is being verified for accuracy.

This is not a diagnosis. The calculations that are provided are estimates based on averages.

Babyvue: Pregnancy Due Date Calculator

If you want to plan ahead, or have just found out you are pregnant, our Pregnancy Due Date Calculator will give you an estimation of when you are due, adding another piece to the puzzle of this exciting journey you are embarking on.

You've found out you are pregnant, now what? Gathering as much information as you can to plan your pregnancy is extremely helpful in making this time go smoothly. Let us help you understand your pregnancy timeline so you know when you are due, when to get your medical scans, book appointments, prepare for maternity leave and when to come to see us at Babyvue for scans. Use our Pregnancy Due Date Calculator now to have more knowledge about your pregnancy journey.

How is my estimated due date (EDD) calculated?

Our personalised Pregnancy Due Date Calculator uses data about your last menstrual period (LMP) to calculate when your baby is most likely to be born. Input the date of the first day of your last menstrual period into our calculator and you will have a better understanding of your pregnancy timeline.

This calculator is based on a 28-day menstrual cycle and is intended as a guide only. If you are looking for the most accurate due date, please discuss this with your NHS-assigned GP, midwife, and medical health professional.

Are there other ways to calculate my due date?

Yes, there are a handful of ways to calculate your due date depending on the method used to become pregnant, how much data you have to hand and how far along in the pregnancy you are.


Your NHS GP will calculate your estimated due date when you have your first prenatal appointment. They will give you an initial estimate based on the date of your last period. You will then be given a dating scan appointment at 10 weeks to 14 weeks pregnant. At this appointment, the doctor will do an ultrasound to measure the fetus and give you a more accurate understanding of how many weeks pregnant you are and when your due date is.

Conception Date*

This calculation is more accurate when methods like IVF are used to become pregnant as you know the precise date of conception. To calculate your due date based on your conception date, add 266 days to the date of conception and you will find your estimated due date.

Gestation Date / Gestation Age*

Gestational age (GA) describes the age of the pregnancy or how long you have been pregnant. This method allows you to find out how far along in your pregnancy you are, rather than giving your estimated due date. For this, you will need to calculate the number of days/weeks between your last menstrual period and today's date. For example, if your last menstrual period was 56 days ago, your baby is 8 weeks old in gestational age.

*Coming soon to our Baby Due Date Calculator

How likely am I to give birth on my due date?

Your estimated date of delivery is never entirely accurate. Approximately 90% of pregnancies will last between 37 and 42 weeks. When your due date is estimated using our calculator, this is based on your pregnancy lasting 40 weeks. With only 5% of births taking place on their 40-week due date, the due date given is just a prediction.

Your due date can also change as you progress through your pregnancy There is no need to worry about this and there are many reasons why this could happen including having irregular periods or an above-average fundal height (the measurement taken from the top of your pubic bone to the top of your uterus), your doctor might revisit this information and update it during your pregnancy. Many factors influence when you give birth as your pregnancy is uniquely yours.

How accurate are due date estimations?

You've probably heard stories about babies being early or late by days and even weeks. Among others, there are two key reasons this can happen.

The first is that the last menstrual period (LMP) data used is based on you having a 28-day cycle with ovulation taking place 14 days into your cycle. Not all women have this cycle length or ovulation window so this can lead to the calculation being incorrect.

The second reason is a little less about the numbers and a little more about you as a person. As each pregnancy and baby is unique, so is the growth of this new life. Because of this, every pregnancy timeline will vary no matter how much data we have.

What to do with the information from our Pregnancy Due Date Calculator

Now that you have an estimated due date, you have more information about your pregnancy journey. This will help you to plan your timeline over the coming months including when to get scans and health check appointments booked.

Here are a few things to pop in the diary but please note, that this is not an extensive list, rather some of the key appointments you can look into further:

  • From 6 weeks: Get a Babyvue SneakPeek Gender Test

  • Between 6 weeks and 14 weeks: Get a Babyvue Early Pregnancy Scan

  • Between 8 weeks and 10 weeks: Have your first contact with an NHS midwife or doctor (or earlier if you know you are pregnant already)

  • Between 8 weeks and 14 weeks: Have your NHS dating scan appointment

  • From 10 weeks: Get a Babyvue Harmony Baby's Health Test

  • Between 16 weeks and 22 weeks: Get a Babyvue Gender Scan

  • Between 14 weeks and 40 weeks: Get a Babyvue Quick Reassurance Scan

  • Between 18 weeks to 20 weeks: You'll be offered an NHS ultrasound scan to check the physical development of your baby

  • Between 24 weeks and 40 weeks: Get a Babyvue Growth & Presentation Scan

  • Between 24 weeks and 32 weeks: Get a Babyvue 4D Scan

  • 25 weeks: You'll have an extra NHS checkup if this is your first baby

No matter what stage of your pregnancy you are in, this is the perfect time to start getting prepared, understanding what is to come and getting organised for the newest member of your family.

Important Notice

This is not a diagnosis. The calculations that are provided are estimates based on averages and are for illustrative purposes only. The calculator, calculations, and information provided on this page is for general, non-specific illustrative purposes only and should not be used as a diagnosis for your pregnancy. Please seek medical advice and follow all medical guidance from your medical professional.

Happy Baby Bumps

Babyvue is here to make sure you and baby are happy and healthy. To make sure you feel welcomed, reassured, and in safe hands throughout your pregnancy and fertility journey. Here’s what our customers have said about their experience at our Orpington baby scan clinic on Google Reviews.

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Based on 460+ reviews
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    Baby Scan

    We had such a great experience at BabyVue in Orpington. As others have mentioned, Elena is lovely and really went above and beyond to make sure we got some great... Charlotte, Verified Review
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    Early Pregnancy Scan

    Fantastic early scan, I was nervous even though it’s our second pregnancy and there was no messing about! Within about 20 seconds of having the ultrasound on... JKW, Verified Review
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    Ultrasound Scan

    The staff were all amazing, very helpful and reassuring. It was lovely to see our little baby moving around and the lady that did our scan was great in... Sam, Verified Review
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    Gender Reveal

    We came back to BabyVue today for a second visit, first was at 11 weeks and this time for an early gender reveal. Another great experience. Very ... Lisa, Verified Review
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    4D Baby Scan

    The most amazing experience, very calm and relaxing. We had the 4D scan and Janene was so patient when the baby was hiding away and finally got the most ... Vicky, Verified Review
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    Gender Scan

    Brilliant experience. Very welcoming, kind, friendly receptionist. Extremely talented sonographer. Exceptional level of knowledge and experience... Roberta, Verified Review
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    Early Baby Scan

    Excellent experience both times I have visited BabyVue. My first impression of the clinic was the friendly and professional approach of the staff who greeted me ... Kathryn, Verified Review
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    Private Ultrasound Scan

    I had a great experience at BabyVue. The staff were professional and friendly. The scans were very clear and the price was very reasonable. I would definitely... Danielle, Verified Review