Due Date Calculator

The estimated due date is calculated by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP). This is the standard method used by healthcare providers worldwide.

This calculator uses the same Naegele rule that doctors use. However, only about 5% of babies are born on their exact due date. Most births occur within two weeks before or after the estimated date.

The first trimester spans weeks 1 through 12, the second trimester covers weeks 13 through 26, and the third trimester runs from week 27 until birth around week 40.

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This tool provides estimates only and is not a substitute for professional medical advice. You should schedule your first prenatal visit as soon as you suspect pregnancy, typically around 8 weeks.