Calculate Conception Date

Calculation Method From Due Date From Current Pregnancy Week From Last Menstrual Period

Choose how you want to calculate the conception date

Due Date

Enter your estimated due date

Current Pregnancy Week

Enter your current pregnancy week (1-42)

Last Menstrual Period Date

Enter the first day of your last menstrual period

Average Cycle Length (Days)

Your typical menstrual cycle length (default: 28 days)

Calculate Conception Date Reset

About Conception Dating

Conception typically occurs 11-21 days after the first day of your last menstrual period, with ovulation usually happening around day 14 of a 28-day cycle.

Calculation Methods:

• From Due Date: Subtract 266 days (38 weeks)
• From Current Week: Calculate backwards from current week
• From LMP: Add 14 days (ovulation) then subtract 2 weeks

Important Notes:

• • Conception date is an estimate
• • Sperm can survive 3-5 days
• • Egg survives 12-24 hours
• • Ultrasound dating is most accurate