EGA Calculator

EGA Calculator

How to Use the EGA Calculator

An EGA Calculator (Estimated Gestational Age Calculator) is a tool that helps pregnant women and healthcare providers determine how far along a pregnancy is, based on the first day of the last menstrual period (LMP). It also provides an estimated due date (EDD).

Why is an EGA Calculator Important?

Pregnancy is usually measured in weeks and days, starting from the date of the last menstrual period. Since ovulation and conception generally occur about two weeks after the LMP, doctors use this method as a consistent starting point. Knowing the gestational age is crucial for:

  • Monitoring fetal development.
  • Scheduling important tests and ultrasounds.
  • Planning prenatal visits.
  • Preparing for delivery.

Steps to Use the EGA Calculator

  1. Enter your last menstrual period (LMP) date into the calculator.
    Example: If your LMP started on June 1, 2025, select that date.
  2. Click “Calculate EGA.”
  3. The calculator will display:
    • Gestational Age (EGA): How many weeks and days pregnant you are.
    • Estimated Due Date (EDD): The predicted date of delivery, usually 280 days (40 weeks) from the LMP.

Example Calculation

  • LMP: June 1, 2025
  • Today’s Date: August 28, 2025
  • Gestational Age: 12 weeks and 2 days
  • Estimated Due Date: March 8, 2026

This tells you how far along the pregnancy is and when you can expect the due date.

Benefits of the EGA Calculator

  • Quick & Easy: No need for manual math—just select a date.
  • Helps Tracking: Ensures timely prenatal care.
  • Provides Clarity: Useful for parents planning maternity leave, baby preparation, and medical visits.
  • Medical Guidance: Offers a reliable estimate aligned with standard obstetric calculations.

EGA Calculator FAQ

Q1: How accurate is the EGA Calculator?
A: It gives a good estimate, but actual conception can vary, especially if cycles are irregular. Ultrasound dating may provide more accuracy in early pregnancy.

Q2: Why is pregnancy counted from the last menstrual period instead of conception?
A: Conception is hard to pinpoint, but the first day of the LMP is a clear, trackable event, so it’s used as the standard reference point.

Q3: Can this calculator adjust for irregular cycles?
A: This basic version assumes a standard 28-day cycle. If your cycle is longer or shorter, your due date may differ.

Q4: What if I don’t remember my LMP?
A: In that case, an early ultrasound can help estimate gestational age more accurately.

Q5: Is the EGA the same as the due date?
A: No. The EGA tells you how far along you are, while the EDD predicts when the baby might be born.

Q6: Do all pregnancies last exactly 40 weeks?
A: No. While 40 weeks is the standard estimate, healthy pregnancies can range from 37 to 42 weeks.