Pregnancy Week Calculator
Enter LMP or conception date on Jenzzy to display weeks pregnant and milestone trimester boundaries.
Inputs
Results
Enter values to see results.
Formula
Gestational days = Today − LMP; Weeks = days / 7
Clinical gestational age counts from LMP, not conception.
Example
- Days: 104 days
- Weeks: 14 weeks 6 days= Week 14
Result: 14 weeks pregnant — second trimester
Frequently Asked Questions
LMP vs ultrasound?
Providers may adjust based on scan measurements.
Trimester cutoffs?
T1 ends week 12; T2 weeks 13–27; T3 from week 28.
Premature?
Delivery before 37 weeks is preterm.