How much pure silver (fine ounces) is in a 90% silver dime?
Executive summary
A U.S. 90% silver dime (pre‑1965) contains roughly 0.07234 troy ounces of pure silver when calculated from the widely cited gross weight of 2.5 grams and the 90% silver composition (2.5 g × 90% = 0.07234 troy oz) [1]. Market listings disagree slightly—some dealers list 0.0715 troy ounces per dime—so investors should be aware of small rounding and convention differences among sources [2].
1. What the question really asks—and why precision matters
The user’s question is narrowly numerical: how many fine (pure) troy ounces of silver are in a 90% silver dime; answering it requires the coin’s gross weight and its silver fineness, then a unit conversion to troy ounces, because bullion pricing and melt‑value math are done in troy ounces (the dime’s 90% composition is a historical standard and the gross weight is the input for the calculation) [3] [1].
2. The straightforward calculation most sources use
Numerous bullion and coin references state that pre‑1965 U.S. dimes were struck at a gross weight of 2.5 grams (0.088 troy ounces) and composed of 90% silver and 10% copper; multiplying 0.088 troy oz by 0.90 yields approximately 0.0723 troy ounces of pure silver per dime, often rounded to 0.07234 troy oz in precise math [1] [3] [4].
3. Why some dealers quote 0.0715 troy oz instead
A number of dealers and retail listings quote 0.0715 troy ounces per dime and use the convenient rule that $1 face value (10 dimes) equals 0.715 troy oz of silver; that convention simplifies inventory and pricing but differs slightly from the 2.5 g × 90% calculation and reflects rounding or alternative weight conventions used in trade pricing [2] [5].
4. Reconciling the two figures without inventing facts
The reporting shows two common figures: ~0.0723–0.07234 troy oz computed from 2.5 g and 90% silver [1] [3] [4], and 0.0715 troy oz cited by several dealers as the industry rule of thumb that gives $1 face = 0.715 oz [2] [5]. Sources do not provide a definitive explanation for the divergence in the snippets supplied, so it is not possible from these sources alone to assert which convention every market actor uses or why a particular dealer chose 0.0715 without further vendor documentation [2] [5].
5. Practical takeaway for valuation and stacking
For precise melt‑value math based on physical measurements, use the coin’s gross weight (2.5 g) and the 90% fineness to calculate ~0.07234 troy oz of pure silver per dime; for many market transactions dealers will price by the common face‑value rule of $1 = 0.715 oz (i.e., 0.0715 oz per dime), so check the dealer’s quoted silver content before trading to know which convention is being applied [1] [2] [5].
6. Alternative viewpoints and implicit agendas in the reporting
Retail and bullion websites have an implicit commercial agenda—simplifying math for sales and packaging—so their rounded or face‑value‑based figures (0.0715 oz/dime) may prioritize convenience over strict gram‑to‑troy‑ounce conversion; independent calculators and reference guides emphasize the gram‑based precise figure (~0.07234 oz) and cite the 2.5 g weight and 90% fineness [2] [1] [4].