Calculating OZ's in 90% coins

[scrapper2010]

Hey all, I'm doing a spreadsheet to keep track of some coins and I'm having trouble figuring up how many ounces of silver are in some 90% denominations. I know that a 90% dollar has .77344 oz's of silver. So to calculate the oz's of silver in a quarter can I just do .77344 divided by 4, which is .19336? Or does it not break down that exact. I tried to look on coinflation to get the grams, then plug that into a grams to ounces calculator but it didn't seem to come out right when I multiplied the answer it gave me by the spot price/oz. Anyone know the silver content, in ounces, in a dime, quarter, and half dollar?

[brian0918]

Click on any of the entries at www.coinflation.com and they give you the oz of silver in each.

[hags]

Dollar .773
90% half .362
40% half .148
Quarter .181
Dime .072
35% Nickel .056


hags

[IdahoCopper]

I've been thinking of this lately. A spreadsheet is needed that calculates the .999 ounces silver in 90% and 40% US coins, as weighed by a gram scale. This would give the exact silver content regardless of the loss to wear on the slick and old coins.

[hags]

I've been thinking of this lately. A spreadsheet is needed that calculates the .999 ounces silver in 90% and 40% US coins, as weighed by a gram scale. This would give the exact silver content regardless of the loss to wear on the slick and old coins.

g = grams

90% coins

g x .9 x .03215 = ozt

40% coins

g x .4 x .03215 = ozt

[Market Harmony]

A $1 coin weighs more than 2 halves, 4 quarters, or 10 dimes... it's just the way they made them... foolish, illogical, but the way it was done...

A dollar (new, unworn) should CONTAIN .7734 ozt of fine silver
Typical 90% coinage (Half, Quarter, Dime) that is circulated and commonly traded as "junk silver" contains 715 ozt of fine silver in a $1000 bag... so, if you work that backwards, then a dollar face value has .715 ozt of fine silver. This number varies with the quality of silver... $10 face of 1964 Kennedy Halves will weigh more than $10 face of Barber Halves

[brian0918]

I've been thinking of this lately. A spreadsheet is needed that calculates the .999 ounces silver in 90% and 40% US coins, as weighed by a gram scale. This would give the exact silver content regardless of the loss to wear on the slick and old coins.

That wouldn't work for 40% halves, because the outer clad layer is a higher silver content (80% silver, 20% copper) than the inner core (20.9% silver, 79.1% copper).

[IdahoCopper]

Here is the spreadsheet for calculating US coins, sterling and 1oz bullion:

http://www.idahocopper.com/AgCoinCalc.xls

[IdahoCopper]

I've been thinking of this lately. A spreadsheet is needed that calculates the .999 ounces silver in 90% and 40% US coins, as weighed by a gram scale. This would give the exact silver content regardless of the loss to wear on the slick and old coins.

That wouldn't work for 40% halves, because the outer clad layer is a higher silver content (80% silver, 20% copper) than the inner core (20.9% silver, 79.1% copper).

So overall, is it 40% silver, or not?

[IdahoCopper]

A $1 coin weighs more than 2 halves, 4 quarters, or 10 dimes... it's just the way they made them... foolish, illogical, but the way it was done...

A dollar (new, unworn) should CONTAIN .7734 ozt of fine silver
Typical 90% coinage (Half, Quarter, Dime) that is circulated and commonly traded as "junk silver" contains 715 ozt of fine silver in a $1000 bag... so, if you work that backwards, then a dollar face value has .715 ozt of fine silver. This number varies with the quality of silver... $10 face of 1964 Kennedy Halves will weigh more than $10 face of Barber Halves

But all US coins, separated by 90% and 40%, and weighed by the gram, will calculate for the same., regardless of dollar or dime coin. Coin silver is the same alloy for all.

[brian0918]

I've been thinking of this lately. A spreadsheet is needed that calculates the .999 ounces silver in 90% and 40% US coins, as weighed by a gram scale. This would give the exact silver content regardless of the loss to wear on the slick and old coins.

That wouldn't work for 40% halves, because the outer clad layer is a higher silver content (80% silver, 20% copper) than the inner core (20.9% silver, 79.1% copper).

So overall, is it 40% silver, or not?

Yes, overall it is 40%, but any wear will only be to the outer layer, not to the inner core, which complicates the calculation.

Using some basic math:

Outer layer weight + inner layer weight = total weight

x + y = 11.50 grams

Outer layer silver + inner layer silver = total silver

0.80x + 0.209y = 0.40*11.50 grams


Solving for x and y, you get that the outer layer weighs 3.72 grams, and the inner core weighs 7.78 grams. So in your calculations, you should assume that the 7.78 grams is unchanged, i.e. that inner core of 1.626 grams Ag is always there.

So any reduction in weight due to wear will only affect the outer 3.72 grams (of which 2.976 grams are silver).

So for a sample 40% half, if the coin weighs 11.40 grams instead of 11.50, that means the outer layer weighs 3.62 grams instead of 3.72. So the amount of silver should be 1.626 + .80*(3.62) = 4.52 grams, instead of 4.60 grams silver in a perfect coin.

Comparing that calculation to just a bare 40% calculation - i.e. 0.40*11.4 grams = 4.56 grams - you see there's not much difference between the two calculations - about .04 grams. But if you're dealing with a lot of halves, then it could add up.

[uthminsta]

Interesting math, for sure. But in most of my dealings, 40% halves trade at under spot price. Wear shouldn't really affect sales prices as much. I also don't see a lot of 40% slicks.

I've always used one simple magic number: Face value times .723 is actual silver ounces.

For dollars, which I buy much less often because there's almost always a premium, the magic number is .773.

[brian0918]

Interesting math, for sure. But in most of my dealings, 40% halves trade at under spot price. Wear shouldn't really affect sales prices as much. I also don't see a lot of 40% slicks.

I've always used one simple magic number: Face value times .723 is actual silver ounces.

For dollars, which I buy much less often because there's almost always a premium, the magic number is .773.

Agreed, wear is not really a problem on a 40% half, so the simpler calculation should be fine.

[brian0918]

Here is the spreadsheet for calculating US coins, sterling and 1oz bullion:

http://www.idahocopper.com/AgCoinCalc.xls

See this thread: viewtopic.php?f=9&t=15209&p=175759#p175759

It seems unlikely that you would be able to account for wear, given the wide discrepancies in weight simply due to minting differences.

[IdahoCopper]

The lower part of the calculator is accurate for weighing bulk coins by the gram. 90% silver alloy is coin silver.

[scrapper2010]

A $1 coin weighs more than 2 halves, 4 quarters, or 10 dimes... it's just the way they made them... foolish, illogical, but the way it was done...

This fact strikes me as very odd. It makes it so that 10 dimes have (slightly) less silver than 4 quarters, which have less silver than 2 halves, which have less silver than 1 silver dollar. So when a person buys a certain FV in 90% coinage it seems to be worth your while to know how much of it is dimes, quarters, halves etc. Especially if buying a large quantity.

[Treetop]

A $1 coin weighs more than 2 halves, 4 quarters, or 10 dimes... it's just the way they made them... foolish, illogical, but the way it was done...

This fact strikes me as very odd. It makes it so that 10 dimes have (slightly) less silver than 4 quarters, which have less silver than 2 halves, which have less silver than 1 silver dollar. So when a person buys a certain FV in 90% coinage it seems to be worth your while to know how much of it is dimes, quarters, halves etc. Especially if buying a large quantity.

the dollars have a base of .7734 ounces of silver per $1. all other coinage it is .723, but people often go by .715 to account for wear. With quarters, dimes and halves that are 90%, any differences in silver levels would be directly related to how much wear the coins have. Although it is true halves fair the best overall, quarters seem atleast as worn as dimes do in my experience, maybe a bit more. People use quarters more often I guess.

[Chief]

Crude and easy way...
14 dimes ~ 1 toz.
$1.40FV/.toz
Not the most accurate, but close.

[68Camaro]

A $1 coin weighs more than 2 halves, 4 quarters, or 10 dimes... it's just the way they made them... foolish, illogical, but the way it was done...

This fact strikes me as very odd. It makes it so that 10 dimes have (slightly) less silver than 4 quarters, which have less silver than 2 halves, which have less silver than 1 silver dollar. So when a person buys a certain FV in 90% coinage it seems to be worth your while to know how much of it is dimes, quarters, halves etc. Especially if buying a large quantity.

Fractional coinage in the early days was exactly proportional to the dollar, which was 27 grams of 89.243% silver.

The coinage act of 1837 changed the alloy to an even 90% silver. The new silver dollar had the same amount of silver, but weighed slightly less overall due to the math.

The coinage act of 1857 devalued the fractional coinage to ~93.1% of the silver dollar, to reduce melt-downs because foreign rates paid were making it favorable to melt the coin and export it.

The fractional coinage from that point to 1964 have each had exactly the same proportional amount of silver:

halves: 25 grams total weight, 90% silver
quarters 12.5 grams total weight, 90% silver
dimes: 6.25 grams total weight, 90% silver

$10 of fractional, no matter the face, is exactly 250 grams of 90% silver. Multiply by .9 to get the grams of silver. Divide that by 31.1 to get the toz of silver.

I've got the whole flippin' history in several tabs of a spreadsheet, but it's easy to make your own.

The only differences between the types are that the smaller coins wear faster than the larger ones, so that circulated dimes have less silver in them, normally, than halves.

[Lemon Thrower]

$1 FV silver dollars has .76 troy ounce of silver.

$1 FV 90% has .715 troy ounce of silver.

$1 FV 40% has .295 troy ounce of silver.

[beauanderos]

A $1 coin weighs more than 2 halves, 4 quarters, or 10 dimes... it's just the way they made them... foolish, illogical, but the way it was done...

This fact strikes me as very odd. It makes it so that 10 dimes have (slightly) less silver than 4 quarters, which have less silver than 2 halves, which have less silver than 1 silver dollar. So when a person buys a certain FV in 90% coinage it seems to be worth your while to know how much of it is dimes, quarters, halves etc. Especially if buying a large quantity.

Fractional coinage in the early days was exactly proportional to the dollar, which was 27 grams of 89.243% silver.

The coinage act of 1837 changed the alloy to an even 90% silver. The new silver dollar had the same amount of silver, but weighed slightly less overall due to the math.

The coinage act of 1857 devalued the fractional coinage to ~93.1% of the silver dollar, to reduce melt-downs because foreign rates paid were making it favorable to melt the coin and export it.

The fractional coinage from that point to 1964 have each had exactly the same proportional amount of silver:

halves: 25 grams total weight, 90% silver
quarters 12.5 grams total weight, 90% silver
dimes: 6.25 grams total weight, 90% silver

$10 of fractional, no matter the face, is exactly 250 grams of 90% silver. Multiply by .9 to get the grams of silver. Divide that by 31.1 to get the toz of silver.

I've got the whole flippin' history in several tabs of a spreadsheet, but it's easy to make your own.

The only differences between the types are that the smaller coins wear faster than the larger ones, so that circulated dimes have less silver in them, normally, than halves.

Nice informational post... quite useful However... to clarify one point. All coins wear at the SAME rate... according to their usage. It is due to the fact that smaller coins are used more often than larger denominations that they may incur slightly greater wear. When the day arrives that price rise dictates the arrival en masse of Chinese counterfeits of 90%, my personal preference would be for the dimes, then quarters, and lastly possession of halves... as the larger coins will fall prey first to faux reproductions as their profit motive would be more easily attained with higher mass items. We're seeing alot of fakes right now at the one ounce round size, you can expect that widespread counterfeiting of 90% WILL someday occur.

[brian0918]

The fractional coinage from that point to 1964 have each had exactly the same proportional amount of silver:

halves: 25 grams total weight, 90% silver
quarters 12.5 grams total weight, 90% silver
dimes: 6.25 grams total weight, 90% silver

That's not what I'm seeing at coinflation:

Halves: 12.5 grams total weight
Quarters: 6.25 grams total weight
Dimes: 2.5 grams total weight

But their silver amounts still work out right. A quarter has 2.5 times the silver of a dime, and a half has 2 times the silver of a quarter.

[uthminsta]

$1 FV silver dollars has .76 troy ounce of silver.
$1 FV 90% has .715 troy ounce of silver.
$1 FV 40% has .295 troy ounce of silver.

Where do you get that?
$1 FV silver dollars has .773 troy ounce of silver.
$1 FV 90% has .723 troy ounce of silver.

[beauanderos]

$1 FV silver dollars has .76 troy ounce of silver.
$1 FV 90% has .715 troy ounce of silver.
$1 FV 40% has .295 troy ounce of silver.

Where do you get that?
$1 FV silver dollars has .773 troy ounce of silver.
$1 FV 90% has .723 troy ounce of silver.

If you're talking BU, then yes. LT was referring to avg circ condition and applying the 715 convention (loosely) to the content of the silver dollar (715/723 x .773 = .764 troy oz)

[68Camaro]

Yeah, a total brain fart. That's what I meant, but wrote it too fast. 12.5, 6.25, 2.5 is correct. Thanks for catching that.

The fractional coinage from that point to 1964 have each had exactly the same proportional amount of silver:

halves: 25 grams total weight, 90% silver
quarters 12.5 grams total weight, 90% silver
dimes: 6.25 grams total weight, 90% silver

That's not what I'm seeing at coinflation:

Halves: 12.5 grams total weight
Quarters: 6.25 grams total weight
Dimes: 2.5 grams total weight

But their silver amounts still work out right. A quarter has 2.5 times the silver of a dime, and a half has 2 times the silver of a quarter.