Things You'll Need
Instructions
Examine the coin. Holding the coin by its edge, look at the obverse (front) and reverse (back) of the coin, paying attention to the wear on the coin and any damage such as cuts or scrapes on the surface. Use a magnifying glass if necessary.
Find the half eagle section in a grading book. Half eagles are also known as five dollar gold coins. There are many books on grading coins, and most are illustrated with photos showing the progression of wear. For example, "uncirculated" coins have no wear, "extremely fine" coins have a little wear on the high points, "fine" coins are well-worn, and "good" coins have only faint details.
Match your coin to the photograph based on wear. Once you match the coin, you have your grade.