Pregnancy Due Date Calculator

Enter the first day of your last menstrual period (LMP). We estimate the due date using the 40-week rule (280 days). This is a standard screening estimate; your provider may use ultrasound for a more precise EDD. Always confirm with your healthcare provider.

Estimate due date

Enter LMP date and click Calculate.

How it works

EDD = LMP + 280 days (40 weeks). We add 280 days to the date you enter and display the result. Actual delivery varies around this date.

When to use it

Use it for a quick estimate. Always confirm with your healthcare provider and follow their dating method.

Frequently asked questions

  • Is 40 weeks from LMP accurate? It is a common rule. Ultrasound in the first trimester often gives a more accurate EDD.
  • What if my cycle is not 28 days? The 40-week rule assumes average cycles. Your provider can adjust for your cycle length.