How Many Grams Is One Ounce of Gold? Understanding USD per Ounce and CNY per Gram

Author: Thomas | Trading Knowledge | November 7, 2026

Summary: International gold quotes commonly use USD per troy ounce, while domestic retail commonly uses CNY per gram. When comparing the two, first unify weight and currency, then check the quote time, purity and actual transaction conventions. The following uses teaching assumptions to demonstrate the conversion; all numbers are worked examples.

Which kind of ounce is used in gold quotes

Precious metals commonly use the troy ounce, and one troy ounce is approximately equal to 31.1035 grams. The avoirdupois ounce commonly used for everyday weighing is approximately 28.3495 grams. Using the latter for gold quotes would overestimate the converted per-gram price. When a quote only says "oz", you can confirm the weight unit it uses from the product description. International spot gold quotes should usually also have their currency checked, to avoid treating a quote displayed in another currency as a USD price.

Convert weight first, then currency

Assume the gold quote is USD 3,100 per troy ounce, and one US dollar can be exchanged for 7.20 CNY. First, divide 3,100 by 31.1035 to get approximately USD 99.67 per gram. Second, multiply this result by 7.20 to get approximately CNY 717.60 per gram. Intermediate calculations should retain enough decimal places, and rounding should be done uniformly at the end. The general formula is: CNY per gram reference price = USD per troy ounce quote ÷ 31.1035 × the amount of CNY exchangeable per US dollar.

The exchange-rate direction determines whether to multiply or divide. If the interface directly states how many CNY correspond to one US dollar, use multiplication. If the data source shows how many US dollars correspond to one CNY, divide the USD per-gram price by this number. You can write the units in the formula to check whether USD and ounces are canceled out in turn, leaving only CNY per gram. Gold quotes and exchange rates should be taken from times as close as possible, especially when comparing intraday changes.

Why store per-gram prices are often different

The conversion result is a reference value obtained by converting the same gold quote by weight and currency. Retail quotes may include labor fees, dealer premiums or other fees, and buyback prices may also use a different pricing rule. Before comparing, confirm whether the listed price is a buy price, sell price or buyback price, whether labor fees are included, and whether the listed price is calculated by finished-product weight or pure gold weight. If a teaching calculation is based on a finished product with a total weight of 10 grams and a gold content of 75%, the pure gold it contains is approximately 7.5 grams. This weight can be used to estimate the reference value of the gold in it, while the actual quote for the finished product still depends on the product and transaction terms.

Check quote units and position units separately

A change in the per-ounce quote in the terminal needs to be multiplied by the number of ounces corresponding to the position to estimate the USD profit or loss. Assume a position corresponds to 2 troy ounces, and the price changes by USD 5 per ounce; then, ignoring fees, the profit or loss range caused by the price change is USD 10, with the direction depending on the position direction. The contract unit per lot may differ across brokers and products; before calculating, check the contract specifications of that instrument and handle currency conversion according to the account currency.

When reviewing, write the original quote, quote time, exchange-rate direction and contract unit on the same record. In this way, even if two pages show different numbers, you can first investigate differences in units, time and fees, and then judge whether the difference is worth further verification.