Pregnancy Due Date Calculator - EDD & Week Tracker
Calculate your pregnancy due date (EDD), current week, trimester, and key milestones based on your last menstrual period or conception date.
About this calculator
This Pregnancy Due Date Calculator gives you three ways to date a pregnancy: from the last period, from your conception date or from an IVF transfer date. Each returns an estimated due date, your gestational age today and a timeline of the main weeks.
Choose the method that fits what you know. The last-period method is the standard. If you know the exact date of conception, the due date is 266 days later. For an IVF transfer, the age of the embryo (3 or 5 days) is taken into account.
How to use it
- Choose how you want to calculate: last period, conception or IVF transfer.
- Enter the date (and your cycle length for the last-period method).
- Press Calculate Due Date to see the due date, current week and milestones.
The three methods
Last period: LMP + 280 days. Conception: Conception + 266 days. IVF: Transfer date + 266 days − embryo age in days. Gestational age is counted from the equivalent of the last period, so it is two weeks ahead of the embryo age.
Worked example
Last period began 1 January 2026
| Due date (40 weeks) | 8 October 2026 |
| Heartbeat detectable (about 6 weeks) | 12 February 2026 |
| End of first trimester (12 weeks) | 26 March 2026 |
| Anatomy scan (about 20 weeks) | 21 May 2026 |
| Viability (24 weeks) | 18 June 2026 |
| End of second trimester (26 weeks) | 2 July 2026 |
| Full term (39 weeks) | 1 October 2026 |
This tool gives general information, not medical advice. Talk to a doctor before making health decisions.
Tips and common mistakes
- If your cycle is regular but not 28 days, adjust the due date by the difference.
- Use your doctor's ultrasound date if it differs by more than a week.
- IVF pregnancies have exact dates, so the estimate is more precise.
- Plan your maternity leave around 37 weeks, not 40.
- Pack your hospital bag by week 36.
Frequently asked questions
How do I calculate my due date from conception?
Add 266 days to the conception date.
What is gestational age?
The time since the first day of the last menstrual period.
What is the difference between early and full term?
Early term is 37 weeks to 38 weeks 6 days, and full term begins at 39 weeks.
How is an IVF due date different?
It is based on the transfer date and embryo age.
Can the due date change?
Yes, your doctor may revise it after an ultrasound.
When is a pregnancy overdue?
After 41 weeks, doctors discuss induction.