The development of a method to grade coins based on their physical condition was a decisive moment for rare coin collectors. While there will always be appraiser judgment involved in classification, the Sheldon Scale established a departure point for the appraiser’s work. With minor alterations over the years, the Scale has remained the standard for grading coin condition.

Dr. William Herbert Sheldon developed the Scale. Sheldon was a well known psychologist in his professional career. He worked with categories professionally defining three body types – endomorphic, mesomorphic and ectomorphic – and defining their influence on behavior. Known as somatotype theory, this work is not seen as valid by many modern psychologists.

Sheldon turned his categorical eye to numismatics when writing Penny Whimsy. Whimsy was the first work to comprehensively describe the varieties of the large cents of early America.

To be useful, a grading system needed to be sufficiently detailed to take into account the very small differences between similar coins. Sheldon related grading to value by his experience. He noticed that “fair” coins would bring double the money that a “poor” coin would bring. A “good” coin rated four times better than “poor.”  As one followed his categories up the line, math showed that a perfect coin would be worth 70 times a poor one.  Thus we know that awkward though it may be, the 70 point scale had a rational basis. Sheldon codified the Scale in 1949.

Major Categories of the Scale

Poor – The coin is badly damaged or smooth so that type is barely discernable.
Fair – The coin is damaged or extremely worn. The type and date are barely discernable.
Good – The coin is overall heavily worn but major devices and features are evident as outlines.

Fine – Wear is moderate but even. The coin shows a distinct rim with all legends readable and clear devices showing some detail.

About Uncirculated – The coin shows only a trace of wear at the highest points. Some mint luster is present. The legends are sharp.
Mint – Being free of any wear distinguishes a mint coin. They may be ugly. They may have poor tone. Zero wear means mint. The Mint category starts at 60. From 60 to 70, subtle qualities such as eye appeal, luster and contact marks gain importance.

Note that proof is a type of coin, not a grade of coin. Proofs are also graded.