Calculation method
Last Period
Free, accurate, week-by-week track
Pregnancy Due Date & Milestone Calculator
Estimate conception timing, due date, and key prenatal milestones from the first day of your last period with a refined, elegant calculator experience.
Conception estimate
June 7, 2026
Due date
February 28, 2027
Trusted prenatal planning
Beautifully organized guidance for due date planning, milestone tracking, and parent-friendly education.
Calculator
Input your dates
Calculation method is fixed to Last Period for a simple and focused workflow.
Today's estimate
274 days remaining
FAQ
Milestones & frequently asked questions
Helpful prenatal guidance for users who want a deeper understanding of due date methods and clinical exceptions.
How is pregnancy week count calculated?
Pregnancy weeks are commonly counted from the first day of the last menstrual period rather than the conception date, which is why gestational age often starts about two weeks before ovulation.
Why does cycle length matter?
If your cycle is longer or shorter than 28 days, ovulation may happen earlier or later. Adjusting the cycle length helps fine-tune conception and due date estimates.
How does IVF change the calculation?
IVF pregnancies are often dated from embryo transfer or fertilization timing, so a last-period model may not be the best fit. Clinical guidance is usually more accurate in assisted reproduction.
Can an ultrasound change the due date?
Yes. First-trimester ultrasound can refine dating when the measured fetal size differs meaningfully from the estimated gestational age, especially when the menstrual cycle is irregular.
Do twins or triplets affect the due date?
Multiple pregnancies are often monitored more closely because they may deliver earlier on average, but the initial due date estimate still usually starts with the same dating rules.