Due Date Calculator

Result

Estimate Based On

First Day of Your Last Period

Average Length of Your Cycles

Pregnancy Timeline

How is the Due Date Calculated?

The most common method to calculate a due date is based on the first day of your last menstrual period (LMP). An estimated due date can be calculated by adding 280 days (40 weeks) to the first day of your LMP. This calculator uses this method and also adjusts for your average cycle length for a more accurate prediction.