Australian Due Date Calculator
Free access. Head to ‘The first fourteen weeks’ for all your early pregnancy questions answered.
Step 1
What would you like to work it out from?
Count from the first day of one period to the first day of the next.
This is the day the egg was released, not the day you had sex. Sperm can wait several days for an egg, so those are often not the same date. If you used a urine test, it picks up the surge before ovulation, so the day after your first positive is usually closer.
Your clinic will have told you this, and it's on your transfer paperwork. Fresh and frozen cycles are worked out the same way.
That's common, and it's not a problem. Fill in your scan below instead.
Step 2
Have you had a scan?
Leave this blank if you haven't had one yet.
Your report may call it the EDD, the EDB, or the estimated date of delivery. They all mean the same thing.
If your report says something like 12+3, that's 12 weeks and 3 days.
Add a date above and your estimate will appear here.
Estimated date of birth
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Why this date
About this date
It is an estimate. It is not an appointment.
The date is worked out by counting 280 days from the first day of your last period, or 266 days from the day you conceived. Both of those assume an average cycle. Yours may not be average, and there is nothing wrong with that.
A scan in the first three months is the most accurate way to set the date, because in early pregnancy all babies are close to the same size. After that they grow at their own pace, and a scan can no longer tell you when the pregnancy began.
Most babies are not born on their date. They arrive somewhere in the weeks around it. A pregnancy that reaches 37 weeks is considered full term, and the great majority of babies are born between 37 and 42 weeks. Even when the date is known exactly, that spread stays wide. Knowing the date more precisely does not make your baby arrive on it.
If your midwife or doctor has given you a date that differs from the one here, theirs is the one your care is based on. Bring any questions about it to them.
