How to Use the Calculator

This tool provides an estimated due date based on different calculation methods. For the most accurate result, use the method that best fits your information:

• Last Menstrual Period (LMP): This is the most common method. Enter the first day of your last period and your average cycle length. The standard cycle is 28 days.
• Date of Conception: If you know the exact date of conception (e.g., through IVF), enter it for a precise calculation.
• Ultrasound: This is often the most accurate method, especially if performed early in the pregnancy. Enter the date of your ultrasound and the gestational age (weeks and days) given by your doctor at that time.

Glossary

Last Menstrual Period (LMP)

The first day your last period started. It's the standard starting point for calculating gestational age.

Estimated Due Date (EDD)

The predicted date of delivery. A full-term pregnancy is typically 40 weeks (280 days) from the LMP. Remember, only about 5% of babies are born on their exact due date.

Gestational Age

How far along the pregnancy is, measured in weeks and days from the first day of the LMP.

Trimester

A pregnancy is divided into three stages called trimesters: First Trimester (weeks 1-13), Second Trimester (weeks 14-27), and Third Trimester (weeks 28 to birth).