Use this numismatic calculation to document a collection, metal content, historical denomination, minting error, grading cost, auction price, or market scenario with explicit measurements and prices.

Cleaned Coin Price (currency)

Required number input.

Original Coin Price (currency)

Required number input.

Measure a cleaning-related observed price difference using otherwise comparable coins; not a universal market discount. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Price Penalty Percent (%)

The resulting price penalty percent returned as a number.

• Coin value and attribution depend on authenticity, date, mint, variety, grade, surfaces, provenance, market liquidity, fees, metal assay, and current spot prices. Images and arithmetic cannot replace expert authentication or in-hand grading.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Retain weight, diameter, photographs, references, transaction fees, and price dates; verify valuable pieces with recognized catalogues and qualified independent experts.

• Grade Gap Price Jump Percent

  Measure an observed price difference between two coin grades relative to the lower-grade price.

• Problem Coin Discount Percent

  Quantify the observed discount of a problem coin against a specified comparable straight-grade coin.

• Premium Over Spot Percent

  Compare a coin's asking price with its metal value; a negative result is a discount.