Pregnancy & Women's HealthACOG Gestational Age Standard

Pregnancy Calculator

Calculates exact gestational age, current trimester, and baby development milestones based on your Last Menstrual Period (LMP) or ultrasound date.

Pregnancy & Women's Health• ACOG Gestational Age Standard

Track pregnancy progress, current week, trimester, and key developmental milestones.

First Day of Last Period (LMP)

Gestational Age: 10 weeks, 0 daysTrimester 1

W1T2 (W14)T3 (W28)Due (W40)

Due DateMay 26, 2027

ConceptionSeptember 2, 2026

Countdown209 days

Evidence-based estimations. Consult a physician for personalized guidance.

Clinical Formula & Calculation Standard

Official clinical definitions and validated mathematical models

Due Date = LMP + 280 Days (40 Weeks) | Conception = LMP + 14 Days

Gestational age counts from the first day of the last menstrual period (LMP). Full term birth occurs between 39 weeks 0 days and 40 weeks 6 days.

Only approximately 4% of infants are delivered on their exact estimated due date; 90% deliver within two weeks.
First trimester: Weeks 1–12; Second trimester: Weeks 13–27; Third trimester: Weeks 28–40+.

Calculate estimated date of delivery (EDD) based on LMP, conception, or IVF date.

Track healthy weekly weight gain targets during pregnancy based on pre-pregnancy BMI.

Find your most fertile days and estimated ovulation dates for the next 6 cycles.