Sheldon Rarity Scale
This seems to be the standard in identifying rarity. This scale was originally designed to identify rarity of Large Cent varieties.
| R1 | Common, readily available |
| R2 | Less common - Available at most shows, but in limited quantity |
| R3 | Scarce - somewhat difficult to find, only a few likely at larger shows |
| R4 | Very scarce - may or may not find at larger shows/auctions |
| R5 | Rare - unlikely more than 5 at shows or auctions each year |
| R6 | Very rare - Almost never seen, only one may be offered for sale in a year’s time |
| R7 | Prohibitively rare - one may be offered for sale once every few years |
| R8 | Unique, or nearly so |
Sheldon Rarity Scale - Expanded
Expanded to three subclasses within each category.
| R1 | Common | R2 | 501 - 1250 Known | R3 | 201 - 500 Known |
| R4- | 161 - 200 Known | R4 | 116 - 160 Known | R4+ | 76 - 115 Known |
| R5- | 61 - 75 Known | R5 | 46 - 60 Known | R5+ | 31 - 45 Known |
| R6- | 25 - 30 Known | R6 | 19 - 24 Known | R6+ | 13 - 18 Known |
| R7- | 10 - 12 Known | R7 | 7 - 9 Known | R7+ | 4 - 6 Known |
| R8- | 3 Known | R8 | 2 Known | R8+ | 1 Known |
The Universal Rarity Scale
Although this one seems to be the most logical scale it does not appear to be widely used with early American copper. It was developed by Q. David Bowers.
| URS 0 | None known |
| URS 1 | 1 known, unique |
| URS 2 | 2 known |
| URS 3 | 3 or 4 known |
| URS 4 | 5 to 8 known |
| URS 5 | 9 to 16 known |
| URS 6 | 17 to 32 known |
| URS 7 | 33 to 64 known |
| URS 8 | 65 to 125 known |
| URS 9 | 126 to 250 known |
| URS 10 | 251 to 500 known |
| URS 11 | 501 to 1,000 known |
| URS 12 | 1,001 to 2,000 known |
| URS 13 | 2,001 to 4,000 known |
| URS 14 | 4,001 to 8,000 known |
| URS 15 | 8,001 to 16,000 known |
| URS 16 | 16,001 to 32,000 known |
| URS 17 | 32,001 to 65,000 known |
| URS 18 | 65,001 to 125,000 known |
| URS 19 | 125,001 to 250,000 known |
| URS 20 | 250,001 to 500,000 known |