Precious metals weight guide
Ounces vs Troy Ounces: Why Precious Metals Use a Different Ounce
An ordinary avoirdupois ounce and a troy ounce are not the same. A troy ounce weighs about 31.1035 grams; an ordinary ounce weighs about 28.3495 grams. Gold and silver markets generally use troy ounces.
The weight difference
One troy ounce equals exactly 31.1034768 grams. One ordinary ounce equals 28.349523125 grams.
That means one ordinary ounce is about 0.911458 troy ounce, while one troy ounce is about 1.09714 ordinary ounces.
Where each ounce is used
The ordinary ounce is common for everyday goods in the United States. The troy ounce is traditional for gold, silver, platinum, and palladium.
Product descriptions should specify the unit; do not assume “oz” means the same thing in every context.
Why the unit matters for pricing
Comparing an ordinary-ounce weight directly with a per-troy-ounce spot price creates an incorrect value estimate. Convert the weight first.
Purity and retail premiums must then be handled separately.
Convert ounces correctly
Use the Troy Ounce Converter to move between ordinary ounces, troy ounces, grams, grains, and pennyweight.
Physical metals research
See How Physical Metals Are Sized and Priced
Compare gold and silver products offered in grams, fractional troy ounces, and full troy-ounce sizes. Check the total delivered price and premium rather than comparing weight alone.
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