PREGNANCY DUE DATE CALCULATOR
Estimates the expected due date based on the first day of your last menstrual period.
INSTRUCTIONS
Enter the first day of your last menstrual period (LMP) and your average cycle length. This calculator uses Naegele’s Rule (LMP + 280 days) to estimate your due date.
Enter the first day of your last menstrual period (LMP) and your average cycle length. This calculator uses Naegele’s Rule (LMP + 280 days) to estimate your due date.
Date
days
Result: Please enter your LMP date.
Naegele’s Rule:
Add 280 days (40 weeks) to the first day of your last menstrual period (LMP).
Example:
If LMP = January 1, 2025 → Expected Due Date = October 8, 2025
PREGNANCY MILESTONES
Add 280 days (40 weeks) to the first day of your last menstrual period (LMP).
Example:
If LMP = January 1, 2025 → Expected Due Date = October 8, 2025
PREGNANCY MILESTONES
| Trimester | Weeks | Typical Development |
|---|---|---|
| First Trimester | 0 – 13 weeks | Formation of vital organs and heartbeat begins. |
| Second Trimester | 14 – 27 weeks | Baby movement felt, anatomy scans performed. |
| Third Trimester | 28 – 40 weeks | Rapid growth and preparation for birth. |