Description
metalRatio = newWeight*newFineness/(oldWeight*oldFineness); metalLossFraction = 1-metalRatio.
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.
metalRatio = newWeight*newFineness/(oldWeight*oldFineness); metalLossFraction = 1-metalRatio.
When to use this tool
Use Historic Currency Debasement Metal Ratio when checking supplied coin or precious-metal quantities.
How to use the tool and how it works
- Enter oldWeight, oldFineness, newWeight, newFineness. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read metalRatio, metalLossFraction. Use the output convention below.
Require positive oldWeight and oldFineness <= 1, nonnegative newWeight and newFineness in [0,1]. metalRatio = newWeight*newFineness/(oldWeight*oldFineness); metalLossFraction = 1-metalRatio.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| oldWeight | Old Weight | Required. Finite number; strictly above 0. |
| oldFineness | Old Fineness | Required. Finite number; maximum 1; strictly above 0. |
| newWeight | New Weight | Required. Finite number; minimum 0. |
| newFineness | New Fineness | Required. Finite number; minimum 0; maximum 1. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| metalRatio | Metal Ratio | Required. Finite number. |
| metalLossFraction | Metal Loss Fraction | Required. Finite number. |
{
"input": {
"oldWeight": 10,
"oldFineness": 0.9,
"newWeight": 9,
"newFineness": 0.8
},
"output": {
"metalRatio": 0.8,
"metalLossFraction": 0.19999999999999996
}
}Limitations and assumptions
- Weights share a mass unit and fineness is a fraction. Metal gain produces a negative loss; face value, seigniorage, legal standards and purchasing power are not inferred.
- 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
- Coin Metal Content Fineness Term
fineGrams = (grossGrams-wearGrams)*fineness.
- Coinage Face Fine Weight Gap
fineMass = grossMass*fineness; gap = fineMass-referenceFineMass.