Coins are Graded on A Numeric Scale from 1 – 70 Called The Sheldon Scale of Coin Grading. Below are Some Sample Coins on A Variety of Grades for The Washington Quarter.
Below That Is A Table That Shows The Grading Scale, Abbreviations, and Description of Each State.
Sheldon Coin Grading Scale
At the heart of finding quality coins and getting a good deal is understanding how to grade coins. Half science half art, the skill of grading coins can be learned with time and use.
The only way to get better at this is to practice, practice, practice. Take your loupe and magnifier and go and visit coin shows and shops to see examples of how different coins are graded. When trying to determine the value of a coin try to see multiple coins in the same grade and rarity you are after. Especially before you make a big purchase you will want to see many different grades of that same coin to ensure you are getting what you paid for.
This is why it helps to specialize in a subset of coins, so if you’re only trying to collect 1800 silver dollars, it will make it much easier to grade seeing the same types of coins over and over.