Pregnancy Calculator
Calculate your pregnancy due date, current week, trimester, and key milestones from your last menstrual period (LMP).
Input Parameters
Results
Pregnancy Timeline
Pregnancy lasts about 40 weeks from the first day of your last menstrual period (LMP). The due date is an estimate — only about 5% of babies are born on their exact due date. Always confirm with your healthcare provider via ultrasound.
What is the Pregnancy Calculator?
The Pregnancy Calculator provides expecting mothers with a comprehensive timeline of their pregnancy journey. It calculates your estimated due date, tracks your current trimester, and outlines major fetal development milestones week by week.
How It Works (Formula)
A standard human gestation period lasts exactly 280 days (or 40 weeks) from the first day of the last menstrual period (LMP). The calculator maps out the 40-week timeline by adding 280 days to your LMP date.
$$ \text{Estimated Due Date (EDD)} = \text{LMP} + 280 \text{ days} $$
The standard medical formula for calculating a full-term pregnancy.
How to Use It
Enter the date of the first day of your last menstrual period (LMP) and your average cycle length. The tool will immediately generate your due date, current weeks pregnant, and the exact dates your trimesters will begin and end.