Pregnancy Conception Calculator

The Pregnancy Conception Calculator estimates the date of conception based on your expected due date, last period date, or ultrasound date. It also provides a possible range of days when conception might have occurred.

Calculate Based On:

Your Due Date

First Day of Last Period

Ultrasound Date

Expected Due Date

First Day of Last Period

Ultrasound Date Weeks Pregnant at Ultrasound

Conception Date Results

Most Likely Conception Date:

Possible Conception Window:

Estimated Due Date:

Note: The conception window accounts for sperm viability (3-5 days) and the fertile period (5 days before ovulation). These dates are estimates only.