How is the due date calculated?

This calculator uses Naegele's rule, a standard method for estimating a due date. It works by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP). This assumes a regular 28-day cycle.

How accurate is this due date?

This is an estimate. Only about 5% of babies are born on their exact due date. Your healthcare provider may give you a more accurate date based on an ultrasound. This online calculator is a great starting point, but is for informational purposes only.

Is this calculator free and private?

Yes, this is a 100% free online tool. All calculations are done in your browser, and none of your personal health information is stored or transmitted.

Pregnancy Due Date Calculator | Conversores Online

Pregnancy Due Date Calculator

Estimate your baby's due date.

Pregnancy Due Date Calculator

Estimate your baby's due date based on the first day of your last menstrual period.

First Day of Last Period

How to Use the Free Online Due Date Calculator

Click the date input field and select the first day of your last menstrual period (LMP).
Press the 'Calculate Due Date' button.
Our online tool will instantly provide you with your estimated due date, your current gestational age (how many weeks pregnant you are), and a progress bar. This service is completely free.

Frequently Asked Questions