100-Point Coin Grading Scale Created by Ron Guth


Award-winning author, researcher and professional numismatist Ron Guth of Expert Numismatic Services, Inc. in San Diego, California (www.ExpertNumismatics.com) has created The Guth 100 Point Coin Grading Scale℠, a new numerical grading scale that he believes will benefit collectors.

1937 Oregon Trail 50c
This 1937-D Oregon Trail commemorative half dollar that grades MS66 on the Sheldon scale is MS92 on The Guth 100 Point Coin Grading ScaleSM

The possibility of a 100 point rare coin grading scale has been discussed and debated for decades because the 70 point grading scale is difficult to explain and it does not provide enough grading points on the high end.

"The Guth 100 Point Coin Grading Scale leapfrogs over the old Mint State and Proof grades from 60 to 70 and creates 20 new Mint State and Proof grades from 80 to 100. The new system complements and integrates the old 70 point system, leaving the grades below 60 intact," said Guth, former President of Professional Coin Grading Service and PCGSCoinFacts.com.

Ron Guth
Ron Guth of Expert Numismatic Services, Inc.

"My goal was to create a new system that could be implemented simply and easily in conjunction with the old," he explained.

"The rare coin market has used a 70-point system developed in 1948 by Dr. William Sheldon, originally for use with U.S. large cents minted from 1792 to 1814. In the 70 years since the Sheldon scale was developed, coin grading has changed dramatically. Converting to a 100 point system is a logical and necessary next step," Guth stated.

"The biggest advantages of this new system are that it achieves the goal of a 100 point scale with minimal disruption to the existing 70 point Sheldon scale, it provides 20 whole numbers for Mint State and Proof grades, and it makes it easier to explain coin grading to current and potential collectors," he commented.

Why the need for 20 grading points on Mint State and Proof coins?

"Currently, the coin market squeezes plus or half grades, known as split grades, into the 60 to 70 range. The Guth 100 Point Coin Grading Scale assigns whole numbers to split grades and eliminates decimals, rounding and pluses," said Guth.

A detailed explanation of Guth’s 100 point scale and a chart mapping the Sheldon 70 point scale to The Guth 100 Point Coin Grading Scale can be found at www.ExpertNumismatics.com.

For additional information or licensing opportunities, contact Ron Guth at Expert Numismatic Services, Inc. at 858-349-8270 or info@ExpertNumismatics.com.

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I can see it now – 2020 silver American Eagle in MS 100 for a cool $2 mil on HSN




I don’t see how 30 more points are going to change anything .I still can’t tell the difference between a 69 or 70 so enough already


Gary, I was at a Coin Show last weekend and an ANACs representative there taking submissions said the exact same thing to me regarding 69 vs 70.


The 1-70 scale is just our quirky numismatic thing. Decimalizing it really does nothing except take away the scale’s charm. From the way I see things listed, I don’t think Sheldon ever intended the full numerical range of the scale to be used. 1, 2, 3, 4, 6, 8, 10, 12, 15, 20, 30, 35, 40, 45, 50, 55, 58, 60, 63, 65, and 67 seemed sufficient. Everything else is just splitting hairs. Personally I never liked that coins were getting 70 grades anyway. 70 seemed more like a theoretical grade than one which could possibly be made by man.… Read more »


So everyone who used the 70 point grading system will have to re-submit to be graded in the 100 point system? Sounds like a money maker for the grading services. You have a coin graded 70? You must re-submit! 80 -100 is the new standard! Kah-ching! Plus we will have a special label for you for an additional $$$ Tsk, tsk.


Why stop at 100? Keep on going higher. You tell me how to tell the difference between a 90 and 100? Just makes the hobby more confusing. Anything for the almighty dollar. Hate to say it, but our hobby is going to self destruct. We need to make the hobby less complicated, not more.

Chas Barber

I made one that goes to 101, 101 is purrfect, like buttah


No thank you!
This will only cause more confusion and breed grading scams.
A resounding NO from this collector.


Sounds like a person that wants to leave there mark on the coin collecting world
What good would a revised grading system do for the hobby?
While I’m on my soap box, what is the reason for PCGS to change their holder so that the new graded coins are too wide to fit in the older PCGS cases. I guess some genius at PCGS whats to sell more plastic. Just what this hobby needs more plastic!