PERS 05

Pregnancy Due Date Calculator

Estimate your due date and current week of pregnancy based on your last menstrual period (LMP).

First day of your last menstrual period

Average cycle length (days)

—

Estimated due date

—

Current week of pregnancy

—

Trimester

This uses Naegele's rule (LMP + 280 days, adjusted for cycle length), the standard method for a first estimate. Only about 5% of babies arrive exactly on their due date — an ultrasound-based estimate from your doctor is more precise than this calculation alone. This tool is not a substitute for prenatal care.