Pregnancy Week Calculator
Calculate your exact pregnancy week and get personalised milestones, scan dates, and baby development updates.
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.
Build Your UK Pregnancy Timeline
Enter a date to see your week, countdown, NHS milestone windows, and practical next steps.
Your Weekly Pregnancy Journey
Knowing exactly which week of pregnancy you are in helps you understand what is happening with your baby's development and what changes you might be experiencing in your own body.
Key UK Milestones
- Booking Appointment: Usually between weeks 8 and 10. This is your first official NHS appointment.
- Dating Scan: Usually happens between weeks 11 and 14. This scan will give you a confirmed estimated due date (EDD).
- Anomaly Scan: Carried out between weeks 18 and 21 to check the physical development of your baby.
Disclaimer: This calculator provides an estimate based on standard medical guidelines (typically calculating 280 days from the first day of the last menstrual period). Every pregnancy is unique. Please consult your midwife or doctor for professional medical advice.
Sources and further reading
Checked for UK pregnancy planning guidance in July 2026.
- NHS Pregnancy Guidance
- NHS: Ultrasound scans in pregnancy
- NHS Start for Life: Pregnancy
- RCOG patient information
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.