When Is My 12-Week Scan?
Enter your due date or the first day of your last period to estimate the usual NHS dating scan window.
This page is for general pregnancy planning and date guidance only. It is not medical advice, diagnosis, or treatment. Pregnancy dates are estimates and can change after a scan or advice from your midwife, GP, or maternity team.
If you have symptoms, concerns, or questions about your pregnancy, speak to your midwife, GP, or maternity team. For urgent help, use NHS 111; call 999 in an emergency. Read how we source and review content in our editorial policy.
12-week scan window calculator
Enter either your due date or the first day of your last period to estimate the usual 11 to 14 week NHS dating scan window.
About Your NHS Dating Scan
In the UK, your first official NHS ultrasound is commonly known as the "12-week scan" or the "dating scan". However, it rarely happens at exactly 12 weeks pregnant.
In England, hospitals usually offer this scan between 11 and 14 weeks. Your local maternity team will confirm the appointment date.
What happens at the 12-week scan?
- Confirm the due date: The sonographer will measure the baby from head to bottom (crown-rump length or CRL) to give you a more accurate Estimated Due Date (EDD).
- Check development: They will check the baby's heartbeat and basic physical development.
- Screening: You may be offered the combined screening test for Down's syndrome, Edwards' syndrome, and Patau's syndrome.
- Multiples: They will check if you are expecting twins or more!
Sources and further reading
Checked for UK 12-week dating scan timing guidance in July 2026.
We prioritise official NHS and GOV.UK guidance, then relevant professional-body information where needed.
Source links are checked on the review date shown above. Your midwife, GP, maternity team, fertility clinic, or employer can give advice that is more specific to your circumstances.