Trimester Timeline Calculator
Map your pregnancy timeline with trimester dates, key milestones, appointments, and developmental markers.
Results
Visualization
How It Works
Pregnancy is divided into three trimesters: weeks 1-13 (development foundation), weeks 14-27 (growth and movement), and weeks 28-40 (maturation and preparation).
The Formula
Trimester 1: Weeks 1-13 | Trimester 2: Weeks 14-27 | Trimester 3: Weeks 28-40
Remaining = Due Date Week - Current Week
Variables
- Viability — Week 24 — point at which survival outside the womb is possible with intensive care
- Full Term — Week 37+ — baby is considered fully developed
Worked Example
At week 20: Second trimester, 50% through pregnancy, 20 weeks remaining. Next milestone: Anatomy scan.
Practical Tips
- Keep a list of questions for each prenatal appointment.
- The anatomy scan at ~20 weeks is when many parents learn the sex.
- Kick counts become important in the third trimester — track daily.
- Pack a hospital bag by week 36.
- Schedule your maternity leave to start around week 37-38.