Pregnancy Calculator

Calculate due date and gestational age from LMP or ultrasound.

Calculate from

Last menstrual period (LMP)

Important Notice

This calculator uses Naegele's rule (LMP + 280 days). Actual delivery date may vary. Always confirm with your doctor.

About the Calculator

Naegele's Rule

The expected due date is calculated by adding 280 days (40 weeks) to the last menstrual period (LMP). This method assumes a regular 28-day menstrual cycle.

Trimesters

1st Trimester: 0-12 weeks
2nd Trimester: 13-27 weeks
3rd Trimester: 28-40 weeks

Important Milestones

12 weeks: End of 1st trimester

20 weeks: Mid-pregnancy

24 weeks: Fetal viability

37 weeks: Full term

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