Due Date Calculator

Estimate your pregnancy due date and current gestational age from your last menstrual period.

Estimated due date
How far along
Trimester

How to use

  1. Enter the first day of your last menstrual period (LMP).
  2. Adjust your average cycle length if it differs from 28 days.
  3. See your estimated due date, how far along you are, and the trimester.

Frequently asked questions

How is the due date calculated?

It uses Naegele's rule: 280 days (40 weeks) from the first day of your last menstrual period, adjusted for cycle length. Only about 4% of babies arrive on the exact date.

Is this a substitute for medical advice?

No. This is an estimate for general information only. Always confirm dates with your healthcare provider, who may adjust them based on an ultrasound.

🔒 This tool runs entirely in your browser. Nothing you enter is uploaded, logged, or stored.

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