Pregnancy Trimester Calculator
Pregnancy Trimester Calculator
Find your due date, current week, and trimester — plus a timeline of what’s ahead — from your last period, due date, conception date, or IVF transfer date.
Estimates only. Due dates calculated this way are a statistical average — only about 1 in 20 babies actually arrive on the exact predicted date. Your provider’s dating, especially from an early ultrasound, takes priority over this calculator.
Where are you starting from?
Pick whichever date you actually know — the calculator converts it internally.
–
You are currently
–
Estimated due date
–
Days to go
First trimester
Second trimester
Third trimester
You are here
About the numbers: due date is calculated as 280 days (40 weeks) from the first day of the last menstrual period, or the equivalent conception-adjusted date for the other input methods. Trimesters are set at weeks 0–13, 14–27, and 28–birth.
Nothing entered here is saved, transmitted, or stored — all calculations run locally in your browser.