Pregnancy Due Date Calculator
Calculate your estimated due date based on your last menstrual period. See trimester, milestones, and conception date.
Estimated Due Date
September 15, 2026
196 days to go
Current Week
12w 0d
Trimester
First Trimester
Estimated Conception
December 23, 2025
Week 0Week 40
Key Milestones
✓ Week 6Heartbeat detectable
✓ Week 8All major organs forming
✓ Week 12End of first trimester
○ Week 16May feel first movements
○ Week 20Anatomy scan / halfway point
○ Week 24Viability milestone
○ Week 28Third trimester begins
○ Week 36Baby is considered early term
○ Week 37Full term begins
○ Week 40Due date
Frequently Asked Questions
How is the due date calculated?+
Using Naegele's rule: add 280 days (40 weeks) to the first day of your last menstrual period (LMP). This assumes a 28-day cycle — the calculator adjusts for different cycle lengths.
How accurate is a due date calculator?+
Only about 4% of babies are born on their exact due date. Most arrive within 2 weeks before or after. The due date is an estimate — your healthcare provider may adjust it based on ultrasound measurements.
What is the conception date?+
Conception typically occurs about 14 days after the first day of your last period (at ovulation). This is adjusted for cycle length — longer cycles mean later ovulation.