Use the following calculator to determine the silver value in various amounts and combinations of 90% junk silver coins and war nickels. Often sellers on eBay will have lots with different combinations of junk silver. I made this calculator so I easily determine the value of the lots. You can also use this calculator to determine the total value of all your junk silver.
To calculate the value of silver in a coin, multiply the silver weight in troy ounces (not the coin weight) by the silver spot price. For example, A junk silver quarter has a silver content of 0.1808 troy oz. If the silver spot price is $10/troy oz then the quarter's value is $10 * 0.1808 = $1.81. This calculator will factor in 1% loss of silver due to wear from circulation (which is common in junk silver coins). The seller will often add about 5% to 15% markup.
Junk silver is usually sold by the face value of the coins. Use this calculator to determine the silver value of 90% junk silver coins when you know the face value of the coins. This calculator does not work for silver dollars or war nickels.
Silver Value = Spot Price * (Face Value * 0.715)
Sometimes junk silver is sold by the total weight of the coins (not the weight of the silver content) in troy ounces. Use this calculator to determine the silver value of 90% junk silver coins when you only know the total weight of the coins.
Silver Value = Spot Price * (Weight * 0.9)
Sometimes sellers (usually on eBay) will offer an auction of junk silver sold by the total weight of the coins in standard ounces or pounds. (1 pound = 16 ounces)
Silver Value = Spot Price * ((Weight * 0.9115) * 0.9)
Enter the junk silver face value of your coins and how much you paid to calculate the premium.
Premium = Amount Paid / (Spot Price * (Face Value * 0.715))
Enter the silver weight (for junk silver, you may need to use one of the previous calculators to determine the silver weight) and how much you paid to calculate the premium.
Premium = ((Amount Paid / Silver Weight) - Spot Price)
Notes concerning face value and weights of 90% junk silver (does not apply to war nickels, 40% halves or dollars):