Patient tools

LMP & gestational age calculator

Estimate your pregnancy timeline, gestational age and due date from the first day of your last menstrual period.

Enter your LMP date

The first day of your last menstrual period.

Last menstrual period (LMP)

Your pregnancy timeline

Estimated conception date—

Current gestational age—

Expected due date—

Current trimester—

Weeks until due date—

About LMP dating

The Last Menstrual Period method is the most common way to calculate pregnancy dates, using the standard 280-day (40-week) pregnancy length from the first day of your last period.

Important notes

Estimates assume a regular 28-day cycle.
Individual pregnancy lengths may vary.
Always consult your healthcare provider for accurate dating.
Ultrasound measurements may provide more precise dating.

Recommended scans

6–8 weeks — early pregnancy viability scan
11–14 weeks — NT scan (nuchal translucency)
18–22 weeks — detailed anomaly scan
28–32 weeks — growth scan (if indicated)

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