Weight guide
Gold bar sizes explained
Weight changes the entry price, relative premium, storage footprint and how easily a holding can be divided later.
Common retail gold bar sizes include 1 g, 2.5 g, 5 g, 10 g, 20 g, 1 troy ounce and 50 g or 100 g. One troy ounce is 31.1035 g. Smaller bars offer flexibility; larger bars often reduce the fabrication premium per gram.
Reviewed September 2026
What to know first
1 troy ounce = 31.1035 grams.
A 1 oz bar is not the same as a 1 avoirdupois ounce bar.
Premium per gram commonly falls as bar size rises.
Keep certificates and tamper-evident packaging intact where supplied.
Small gram bars
Bars from 1 g to 5 g lower the cash needed for one unit and make a holding easy to divide. Their manufacturing and packaging cost is spread across less gold, which can raise the relative premium.
Mid-size bars
Ten gram, 20 gram and 1 oz bars balance unit value with a manageable physical size. Always compare price per gram using the same fineness and current offer.
Larger retail bars
Fifty gram and 100 gram bars concentrate more value in fewer pieces. Consider whether that unit size will suit a future partial sale and whether your storage and insurance arrangements cover it.
Questions answered
Frequently asked questions
How many grams are in one ounce of gold?
Investment gold uses the troy ounce, equal to 31.1035 grams.
Is a larger gold bar always better value?
It often has a lower relative premium, but price, seller terms and market conditions vary. A larger unit also gives less flexibility for partial resale.
What should be printed on a gold bar?
Common markings include refiner, weight and fineness. Packaging or a certificate may contain additional identifiers.
Primary sources
Use these official references to check specifications and rules that may change.
LBMA — Good Delivery rulesThe Royal Mint — Gold bars