Pregnancy Due Date Calculator

Estimate your pregnancy due date

Whether your pregnancy was planned or a happy surprise, you will need to know the expected date of birth in order to prepare for your child’s arrival. Working this out can sometimes be difficult as you may not know the exact date of conception. However, as long as you know the first day of your last period, your due date can be calculated with a good degree of accuracy using our Pregnancy Due Date Calculator.
There are many reasons why it is important to know the expected day your child will be born. For parents it gives you the chance to plan ahead, to ensure you have practically prepared for your child’s arrival. This will mean having all the equipment they will need, but also ensuring that your and your partner’s employer is aware of when there may be a need to have time off work.
Doctors also need to know the expected due date to allow them to plan the maternity services you will require. It allows them to estimate the requirements of the maternity ward you will be using and make sure there are enough resources in place. Additionally, a doctor will use the due date to work out how large your child should be and that it is developing correctly. This will give them the chance to intervene at an early stage if your baby isn’t growing as expected.
How does pregnancy work?
Your baby is conceived when you ovulate and release an egg ready for the sperm to fertilise it. If you have sex around the time of ovulation you are more likely to become pregnant. However, it is hard to know exactly when this happens. It is estimated that a woman will release an egg around 2 weeks after the first day of her last period. This is how the due date calculator works - it takes this date and uses it to estimate the time of ovulation.
A normal pregnancy gestation period is 40 weeks, so this is added to the time of ovulation to come up with an expected due date. It is a method that has been used for many generations and is considered to be very accurate. However, you may find that a clearer picture of the age of your baby will come during an ultrasound scan where measurements can be taken to determine exactly how many weeks pregnant you are.
Pregnancy calculators are not always perfect
Even with a pregnancy due date calculator, it is important to realise that your due date is not entirely guaranteed. Babies will often arrive early for a variety of reasons including fetal distress. In first pregnancies, it is also very common for a baby to arrive later than the due day. Your doctor may even wish to induce the birth if you have passed your due date by a significant number of days - however, this should always be your choice.
For most parents, the thought of their new baby is both exciting and worrying, so knowing as many details as possible about the birth timings will reassure and allow them to prepare themselves and the rest of the family fully.
How the due date calculator works
Our pregnancy due date calculator is a simple tool that will quickly and accurately tell you the expected date of birth of your child. All you need to do is input the details requested and it will quickly give you the date that you can work towards.
pregnancy due date
As you can see you will need to know the date of the first day of your last period and the average length of your menstrual cycle. If you do not know this accurately it is OK to estimate it at 28 days, as this is typical for most women. The length of your cycle will depend on your age and if you have suffered any illnesses or stress in the period leading up to conception. However, it is recommended that you should track your periods while you are trying to conceive to see the length and to accurately know the exact day your period began.
The calculator takes these two pieces of information and works out the day your baby is likely to be born. You can use this as a relatively accurate day to work towards - although remember that babies run to their own schedule and you need to be prepared for dates that fall either side of this one.
For women who have conceived by accident, this due date calculator may not be as accurate as you may not have tracked your periods. However, if you can guess as close as possible, this will still offer a reasonable degree of accuracy.
No matter when your child arrives, this is a wonderful time and so exciting for prospective parents. Enjoy it and don’t worry too much about whether your baby will arrive on the due date. You will be prepared for their arrival and amazed when it finally happens.