Troy ounce to grams converter

Convert troy ounces, grams and other gold units

Type an amount, pick its unit, and the table fills in every other unit. Choose a purity and currency to see what that much gold is worth at today's spot price (the live wholesale price per troy ounce). You can type your own spot price instead.

The unit conversions are exact to the decimals shown. The gold value is a melt value, not a dealer price. Last price update: Loading.

How do you use the converter?

1. Enter the weight printed on the coin, bar or receipt. Use the gold content if you know it; for bullion that is the "1 oz" or "100 g" on the item.
2. Pick the unit it is in. Jewellery is usually in grams, scrap quotes are sometimes in pennyweights, and Gulf and South Asian bars in tola.
3. Set the purity. For bullion stated as "1 oz fine gold", leave it at pure gold. For a gross weight of 22ct or 9ct metal, choose that purity so only the gold is valued.
4. Read the result. The table shows every unit; the line underneath gives grams, troy ounces and the value at spot.

Need a value for a whole coin collection or a box of broken jewellery? The coin melt value calculator has coin presets, and the scrap gold calculator handles mixed carats. All our tools are listed under all gold calculators.

What is the formula for troy ounces to grams?

The figure is exact because of how the units are built. NIST's guide to conversion factors gives the troy ounce as 480 grains, and since 1959 the grain has been fixed at exactly 64.79891 mg. Multiply them and you get 31.1034768 g with no rounding. The ordinary ounce on food packets is 437.5 of the same grains, or 28.349523125 g, so a troy ounce is 1.097143 ordinary ounces. For the history behind the unit, read what a troy ounce is.

Troy ounces to grams: conversion table

Rounded to four or five decimals. The 400 oz row is the nominal weight of a wholesale Good Delivery bar; real bars vary, as explained in what Good Delivery gold is.

Grams to troy ounces: conversion table

Which units are used for gold, and how big are they?

Troy ounce, pennyweight, grain and avoirdupois ounce from NIST SP 811. The tola is conventionally 180 grains, which gives the figure shown.

What about the tael and the baht? Both are used for gold in East and South-East Asia, but their gram weight depends on the market. Hong Kong's gold exchange, for example, quotes its 99 Tael Gold contract per "tael troy", which is not the same as the everyday Hong Kong tael. Because we could not confirm exact figures from an official source, we do not include them in the converter. If you buy in taels or baht, ask the dealer for the weight in grams and enter that.

What is gold worth in each unit right now?

Spot-based values for pure gold, not dealer prices. Updated: Loading. Country pages: US gold price per gram, UK gold price per gram.

How much gold is in common coins and bars?

Coins are often heavier than their gold content because 22 carat coins are alloyed with copper or silver. The converter values gold content, so use the "fine gold" column.

Coin weights from the issuers (US Mint, Royal Canadian Mint, Perth Mint, Royal Mint) as recorded in our coin guides; Vreneli fine gold is our calculation (6.45 g x 90%). Bars assumed 99.99% gold and valued at their stated weight. Values are spot-based. Updated: Loading. All sizes: gold bar sizes.

Worked examples

How many grams is 2.5 troy ounces?

2.5 x 31.1034768 = 77.7587 g. A 2.5 oz holding is about 78 g, a little less than a 100 g bar.

What is the price per gram if gold is US$4,186.10 an ounce?

That was the gold-api.com spot price at 07:34 UTC on 12 October 2026. Divide by 31.1035: US$4,186.10 / 31.1035 = US$134.59 per gram. A common mistake is dividing by 28.35 (the ordinary ounce), which gives US$147.66 and overstates the value by about 9.7%.

What is a 10 g, 22 carat chain worth in gold?

Multiply the weight by the purity, then by the gram price: 10 g x 0.9167 = 9.167 g of pure gold. At US$134.59 per gram that is about US$1,233.75 at spot. A scrap buyer will pay less than this; see our guide to gold premiums explained for why buying and selling prices sit either side of spot.

A buyer offers a price per pennyweight. How does it compare?

Divide a per-dwt price by 1.5552 to get the price per gram. An offer of US$150 per dwt is US$96.45 per gram, which you can then compare with the live gram price above. The dealer buyback calculator shows how far below spot any offer sits.

This converter gives information, not financial advice. For a fuller valuation, try the gold value calculator.

Not financial advice. GoldVetted provides general information to help you compare options. It is not personal financial, tax or legal advice. Gold prices go down as well as up, and you may get back less than you pay. Check tax rules with the official source or a qualified adviser before you act.