Pregnancy Calculator
Enter the first day of your last menstrual period to calculate your due date, current trimester, and pregnancy milestones.
Enter LMP Date
Pregnancy Details
Estimated Due Date
October 22, 2025
Current Week
69w 6d
Trimester
Third
Days Until Due
0
Conception Date
Jan 29
How the Pregnancy Calculator Works
Our pregnancy calculator uses Naegele's rule to estimate your due date by adding 280 days to the first day of your last menstrual period (LMP).
Trimester Overview
- First Trimester (Weeks 1-12) - Major organ development begins
- Second Trimester (Weeks 13-26) - Baby grows and you may feel movement
- Third Trimester (Weeks 27-40) - Final growth and preparation for birth
Pregnancy Calculator FAQ
How is the due date calculated?▼
The due date is calculated by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP). This is known as Naegele's rule.
How accurate is a due date calculator?▼
Only about 5% of babies are born on their exact due date. Most births occur within 1-2 weeks before or after. An ultrasound in the first trimester can provide a more accurate estimate.
What are the three trimesters?▼
First trimester: weeks 1-12 (organ development). Second trimester: weeks 13-26 (growth and movement). Third trimester: weeks 27-40 (final development and preparation for birth).