How is the due date calculated?

The most common method (Naegele's Rule) assumes a standard 28-day cycle and adds 280 days (40 weeks) to the first day of your last menstrual period (LMP).

What if I have an irregular cycle?

If your cycle is significantly longer or shorter than 28 days, this estimate may be off by a few days. Your healthcare provider will likely use an early ultrasound to provide a more definitive 'dating' of the pregnancy.

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Health & Fitness

Pregnancy Due Date Calculator – Milestone Tracking Service | CalcTools

Estimate your due date and track your current gestational progress. Understand the key timelines of your pregnancy journey.

The moment you discover you're expecting, the first question is always: 'When will the baby arrive?' While only about 5% of babies are born exactly on their due date, having an estimated date of arrival is essential for planning, prenatal care, and preparing your home. Our Pregnancy Due Date Calculator provides you with a clear timeline based on the first day of your last period, helping you visualize your journey through the first, second, and third trimesters.

First Day of Last Period

Enter the first day of your last menstrual period to calculate your due date.

How it Works

The tool takes your LMP date and performs date arithmetic to project 40 weeks forward. It also calculates your current 'gestational age' by finding the difference between today's date and your LMP, giving you a real-time progress report.

Calculation Formula

LMP + 280 Days

Calculation Examples

1. **Recent Start**: If your last period began on January 1, your estimated due date would be **October 7** of the same year.

Why use this tool in your daily life?

This tool transforms a abstract concept into a tangible timeline. Knowing your due date allows you to synchronize your life with your baby's development, ensuring you hit every medical and personal milestone with confidence.