Description
fineGrams = (grossGrams-wearGrams)*fineness.
Coin mass, fine-metal content, face value and market value are different historical quantities. Weight and fineness can yield metal content, but metal ratios alone do not establish official standards, authenticity or purchasing power.
fineGrams = (grossGrams-wearGrams)*fineness.
When to use this tool
Use Coin Metal Content Fineness Term when checking supplied coin or precious-metal quantities.
How to use the tool and how it works
- Enter grossGrams, fineness, wearGrams. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read fineGrams. Use the output convention below.
Require nonnegative grossGrams and wearGrams <= grossGrams and fineness in [0,1]. fineGrams = (grossGrams-wearGrams)*fineness.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| grossGrams | Mass before the separate wearGrams deduction under this formula. | Required. Finite number; minimum 0. |
| fineness | Fineness | Required. Finite number; minimum 0; maximum 1. |
| wearGrams | Wear Grams | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| fineGrams | Fine Grams | Required. Finite number. |
{
"input": {
"grossGrams": 10,
"fineness": 0.9,
"wearGrams": 1
},
"output": {
"fineGrams": 8.1
}
}Limitations and assumptions
- grossGrams is the pre-deduction mass under this convention. Avoid subtracting wear again from an already worn measured mass; no numismatic authenticity or current value is established.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use appropriate archival and numismatic evidence for denomination, assay, legal standard and historical market interpretation.
References
Similar or alternative tools
- Historic Currency Debasement Metal Ratio
metalRatio = newWeight*newFineness/(oldWeight*oldFineness); metalLossFraction = 1-metalRatio.
- Coinage Face Fine Weight Gap
fineMass = grossMass*fineness; gap = fineMass-referenceFineMass.