See your likely pregnancy week, trimester and due date.
Pregnancy tracker
Understand your pregnancy timeline.
4Ways to estimate your due date
40Week reference
A pregnancy estimate can support planning, but it does not replace clinical assessment.
Use a date you already know to estimate your current pregnancy week, trimester and due date. Then use the result as a starting point for antenatal planning with your care team.
Use the tracker
An estimate with a purposeEstimate Prepare Confirm
Use the estimate to plan care, not to replace clinical assessment.
Pregnancy dates can help you plan antenatal appointments, scans and birth care. The calculator provides an estimate; your maternity team can confirm the timing of care based on your clinical assessment.
Use the result to organise questions and discuss the next stage of care with your maternity team.
Let your maternity team relate the estimate to your actual pregnancy care.
Your pregnancy estimate
Start with the date you can confirm most reliably.
Choose the method that matches information you already have. If you are not sure about your dates, speak to a doctor or nurse instead of relying only on the estimate.
Privacy note
The calculator runs in your browser. You do not need to submit the result to use the tool.
Pregnant and concerned?
Symptoms and clinical assessment matter more than a calculator estimate.
If you feel significantly unwell or something about the pregnancy worries you, speak to a doctor or nurse rather than relying on the estimated week or due date.
Understanding your estimate
Questions about your pregnancy estimate
The tracker can support care planning, but it should not be used to assess symptoms or delay medical review.
Why can the tracker give a different date from my ultrasound?
Pregnancy can be dated in different ways. Your care team may consider menstrual dates, ultrasound findings and the wider pregnancy history before deciding which estimated date is most useful for your care.
What if I do not know the first day of my last menstrual period?
Use another calculation method only if you genuinely know that information, such as a due date given by your doctor or midwife. If you are not sure about your dates, a pregnancy check with a doctor or nurse is more useful than guessing.
Can I use the result to decide when to start antenatal care?
Use the result for orientation, not as a substitute for care planning. If you are pregnant and have not yet arranged antenatal care, contact the maternity team so the timing of your visits can be based on your actual pregnancy and health history.
What if the tracker result looks reassuring but I feel unwell?
Your symptoms matter more than a calculator. Pain, bleeding, reduced fetal movement later in pregnancy, severe headache, difficulty breathing, labour concerns or any symptom that causes significant concern should be discussed with a doctor or nurse quickly.
Why does the tracker use a 40-week pregnancy reference?
The calculator uses the usual 280-day estimate to estimate pregnancy age and due date. Individual pregnancies vary, and the estimate can be changed by your doctor or midwife when better dating information is available.
Antenatal care
Book Antenatal CareUse your pregnancy dates to support an informed care plan.
Our maternity team can help with antenatal follow-up, birth preparation and the questions that arise along the way.