Pregnancy Calculator

Estimate your baby's due date and track your current pregnancy trimester.

About Pregnancy Calculator

Expecting a baby? The Free Pregnancy Calculator is the Best Due Date Tool to scientifically estimate your delivery date based on your last cycle.

Features

Calculates Estimated Due Date (EDD) using the standard Naegele's rule
Calculates based on Last Menstrual Period (LMP) or Ultrasound Date
Provides a timeline for First, Second, and Third Trimesters
Shows current gestational age (weeks + days)
100% private—no health data is collected

How to Use

Select your calculation method (typically Last Menstrual Period).
Enter the date of the first day of your last period.
Adjust your average cycle length if it is not 28 days.
Click calculate to view your due date and trimester milestones.

Frequently Asked Questions

How accurate is the due date?

Only about 5% of babies are born exactly on their estimated due date. It is perfectly normal to deliver anytime between 37 and 42 weeks.

How does the math work?

The standard medical calculation (Naegele's rule) adds 280 days (40 weeks) to the first day of your last menstrual period.

Why is gestational age older than the baby?

Because doctors start counting from the first day of your last period (about 2 weeks before conception actually occurs), you are considered "2 weeks pregnant" the day you conceive.

Is my data saved?

No. This calculator runs entirely in your browser. We do not store, track, or share any of your health or pregnancy data.

How does it calculate the due date?

It uses Naegele's rule, adding 280 days (40 weeks) to the first day of your last menstrual period (LMP).

Is this date 100% accurate?

No, only about 4-5% of babies are born on their exact predicted due date. It is an estimate.

Can I calculate using conception date?

Yes, if you know the exact date of conception, the tool can calculate from there instead.

Is this a free pregnancy calculator?

Yes, this free pregnancy calculator is completely free to use.

Why use the best due date tool?

It helps expecting mothers plan ahead for doctor visits and baby preparations.

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