If you’ve just found out that you’re expecting, one of the first things you’ll want to find out is when the baby is due. You should be able to work out your due date very quickly with this simple pregnancy calculator method.

Pregnancy Calculator

The length of your pregnancy is calculated using the first day of your last period. Although you didn’t actually conceive on this day, it is usually easier to count from your period than from ovulation. Unless you have been tracking your ovulation, it is impossible to know when the egg was released and fertilised. It usually happens about two weeks after your period began, but it depends on the length of your menstrual cycle.

  • Check the date when your last period started. It is a good idea to keep track of this, especially if you are trying to get pregnant.
  • Add 280 days (40 weeks) to this in order to get your due date.
  • This calculation assumes that you have a cycle of about 28 days. If your cycle is shorter, your due date will be earlier. If your cycle is longer, the due date will be later.

Once you know your due date, you will have some idea of when your baby will arrive. However, it is impossible to know for sure when your baby will arrive. Most babies are born at between 38 and 42 weeks, so your baby may be a little earlier or later than predicted.

What If You Don’t Know When You Had Your Last Period?

The pregnancy calculator relies on knowing the date of your last period. If you aren’t sure when this was, it isn’t possible to work out when you conceived or when your baby was due. However, when you have your first ultrasound scan the doctor or sonographer will be able to give you an estimate date of delivery.