Calculate a mixed collection without forcing every coin into the same weight or purity assumption. Add each coin type separately, including quantity and purity, to obtain both gross and fine-gold weight.
Coin TypeQuantityWeight / Coin (g)Purity (%)
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Gross Coin Weight—
Fine Gold Weight—
Average Purity—
Coin Count—
Packaging Weight—Optional, not included
Mixed Coin Weight Formula
Gross Gold Weight = Σ(Quantity × Weight per Coin)
Fine Gold Weight = Σ(Quantity × Weight × Purity)
Why Average Purity Should Be Weighted
A simple average of coin purities can be misleading if you own very different quantities. The calculator derives collection purity from total fine-gold weight divided by total gross gold weight.
Collection Weight vs Collection Value
This tool intentionally focuses on physical weight and contained gold. Numismatic value, rarity and market premiums are separate valuation questions.
A heavy coin collection is not necessarily a high-value collection solely because of weight.
Frequently Asked Questions
How do you calculate total coin collection weight?
Quantity times weight for each coin type, then sum.