Is this due date calculator accurate?

This calculator provides an estimated due date based on Naegele's rule, which is a standard method assuming a 28-day menstrual cycle. However, it's an estimation. Only about 4% of babies are born on their exact due date. Your actual due date can be affected by cycle length, timing of ovulation, and other factors. A doctor can provide a more accurate date, often confirmed via ultrasound.

What if my cycle is not 28 days?

If your cycle is consistently longer or shorter than 28 days, this calculator's estimate may be less accurate. The due date might be slightly later for longer cycles and earlier for shorter cycles. Your healthcare provider will be able to give you a more precise due date after an ultrasound.

What is gestational age?

Gestational age is the term used to describe how far along the pregnancy is. It is measured in weeks, from the first day of the woman's last menstrual period (LMP) to the current date. A normal pregnancy ranges from 38 to 42 weeks.

Due Date Calculator

Estimate your pregnancy due date based on your last menstrual period (LMP).

Pregnancy Details

First Day of Last Menstrual Period (LMP)

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About the Due Date Calculator

Planning for your new arrival.

How to Use This Calculator

Estimating your pregnancy due date is an exciting first step in your journey to parenthood. Our calculator makes it simple. Just click on the date input field to bring up a calendar. From the calendar, select the first day of your last menstrual period (LMP). This is the only piece of information needed. Once you've selected the date, click the "Calculate Due Date" button. The tool will instantly display your estimated due date, giving you a target date for your baby's arrival. Additionally, it will show you the approximate gestational age of your pregnancy, which tells you how many weeks pregnant you are right now. This is all based on a widely used medical rule, making it a reliable first estimate.

How It Works: Naegele's Rule

This calculator provides an estimate of your due date using a method called Naegele's rule. This is a standard and widely used formula among healthcare professionals to calculate an Estimated Date of Delivery (EDD). The calculation is based on the first day of a woman's last menstrual period (LMP) and assumes a regular 28-day menstrual cycle where ovulation typically occurs on the 14th day.

Due Date = (LMP + 1 Year) - 3 Months + 7 Days

This simple calculation provides a 40-week or 280-day estimate from the start of your LMP. Our calculator also determines your current gestational age by calculating the number of weeks that have passed from your LMP to the present day, helping you track your pregnancy's progress.

Practical Applications

Knowing your estimated due date is more than just exciting—it's a crucial piece of information that helps you and your healthcare provider manage your pregnancy. This calculator is a great first step for:

Planning for Arrival: Getting a general timeline allows you to begin preparing your home, family, and work life for the arrival of your new baby. It gives you a framework for making all the necessary arrangements.
Tracking Milestones: The estimated gestational age is key to tracking your pregnancy week by week. It helps you understand your baby's development, what to expect at each stage, and what changes your body is going through.
Scheduling Appointments: This estimate gives you a basis for scheduling your first and subsequent prenatal visits with your doctor or midwife, ensuring you receive timely care and check-ups.

Frequently Asked Questions

Important Medical Disclaimer

This calculator provides an estimate for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. The due date is an 'estimate'—only a small percentage of babies are born on their exact due date. The actual date can be influenced by many factors, including your individual cycle length, the exact timing of ovulation, and your overall health. For an accurate and reliable due date, it is essential to consult with a qualified healthcare provider who can perform a clinical examination and an ultrasound.