When is my baby due?

Pregnancy due date calculator

First day of your last period (LMP) · How long is your cycle?

How the due date is calculated

Doctors estimate the due date by adding 280 days (40 weeks) to the first day of your last period, and adjust it for cycles longer or shorter than 28 days. Pregnancy weeks are counted from that same day — so at conception you are already about 2 weeks pregnant. Only about 1 in 20 babies arrive exactly on the due date; most come within two weeks either side.

This is an estimate only. Your doctor confirms the date with an ultrasound. Please see a gynaecologist in the first trimester. If you have bleeding or severe pain, go to the nearest hospital straight away.

Your dates stay on your phone. They are worked out right here and are never sent to ProMedicoz, never saved and never shared with anyone.

Frequently asked questions

How accurate is a due date calculator?

It gives a good estimate if your cycles are regular and you remember the date of your last period. An early ultrasound is more accurate, which is why your doctor may change the date after your first scan.

How many weeks pregnant am I?

Pregnancy weeks are counted from the first day of your last period, not from conception. Enter that date above to see your weeks and trimester.

What if my periods are irregular?

With irregular cycles the calculator is less reliable. Your gynaecologist will usually date the pregnancy with an ultrasound instead.

When should I first see a doctor?

As soon as you know you are pregnant, ideally within the first trimester. Your doctor will plan check-ups, tests and supplements such as folic acid.

Read next

  • Think You Might Be Pregnant? Early Signs and First-Trimester Care
  • Antenatal Care: What to Expect at Your Pregnancy Check-Ups
  • Eating for Two? A Sensible Pregnancy Diet Guide (Myths Included)
  • Scans in Pregnancy: What the Ultrasounds Are For and What to Expect
  • Vaccines in Pregnancy: What's Recommended and Why
  • Sugar in Pregnancy: Understanding Gestational Diabetes Calmly
  • Find a gynaecologist