Question 1

How do I calculate my due date?

Accepted Answer

Nuhah's due date calculator adds 280 days (40 weeks) to the first day of your last menstrual period (LMP). This is the standard method used by the NHS and midwives. You can also calculate from a scan date or IVF transfer date.

Question 2

How accurate is a due date calculator?

Accepted Answer

Only about 4% of babies arrive on their exact due date. Most are born within two weeks either side. Your due date is an estimate, not a deadline. A dating scan at 11-14 weeks can refine the estimate.

Question 3

Can my due date change after a scan?

Accepted Answer

Yes. Your midwife may adjust your due date after the dating scan if measurements suggest a different gestational age. The scan-based date is generally considered more accurate than LMP calculation.

Question 4

When will I have my first scan?

Accepted Answer

In the UK, your dating scan typically happens between weeks 11 and 14. This scan confirms your due date and checks your baby is developing well.

Question 5

What if I don't know when my last period was?

Accepted Answer

If you're unsure of your last period date, your midwife will estimate your due date at the dating scan using measurements of your baby. You can also use Nuhah's calculator with a scan date instead.

Due Date Calculator

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