Pregnancy Calculator

Free pregnancy due date calculator. Estimate your due date and track your pregnancy week by week.

How the Pregnancy Calculator works

The due date is calculated using Naegele's rule, which adds 280 days (40 weeks) to the first day of your last menstrual period (LMP). The calculator also determines the estimated conception date (LMP + ~14 days) and identifies your current week and trimester based on today's date.

Formula

Due Date = LMP + 280 days

How to use the Pregnancy Calculator

  1. 1The pregnancy calculator is designed to be simple and fast.
  2. 2Enter the first day of your last period.
  3. 3See your estimated due date and current week.
  4. 4Your result is shown immediately.

Examples

  • LMP Jan 1 = due date Oct 8
  • Shows current week, trimester, and conception date

Benefits

  • Completely free with no signup required.
  • Runs entirely in your browser for instant results and privacy.
  • Works on mobile, tablet and desktop.
  • Results can be copied with one click.

Frequently Asked Questions

Is the pregnancy calculator free to use?

Yes. The pregnancy calculator is 100% free, with no signup, no watermark and no hidden limits.

Does the pregnancy calculator store my data?

No. All calculations and processing happen locally in your browser. Nothing is uploaded to a server.

Does the pregnancy calculator work on mobile?

Yes. The pregnancy calculator is fully responsive and works on phones, tablets and desktop computers.

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