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Grams to Troy Ounces Calculator

Convert between grams and troy ounces in either direction using the exact factor 1 troy oz = 31.1034768 g. Used for gold, silver, platinum, and other precious metals.

Direction

Result

3.2151 troy oz

100 g equals 3.2151 troy oz

Quick Answer

A grams to troy ounces calculator converts between grams and troy ounces using the exact factor 1 troy oz = 31.1034768 g. To convert grams to troy oz: divide by 31.1034768. To convert troy oz to grams: multiply by 31.1034768. For 100 g of gold: 100 / 31.1034768 = 3.2151 troy oz. For 5 troy oz of silver: 5 × 31.1034768 = 155.517 g.

Troy Ounces vs Avoirdupois Ounces: A Critical Distinction

The troy ounce (abbreviated t oz or ozt) is not the same as the standard avoirdupois ounce used in everyday US measurements. One troy ounce equals 31.1034768 grams. One avoirdupois ounce equals 28.3495 grams. The troy ounce is approximately 10% heavier. Precious metals, including gold, silver, platinum, and palladium, are universally priced and traded in troy ounces.

The Troy Ounce Conversion Formula: Exact and Bidirectional

Grams to troy oz: troy oz = grams / 31.1034768 Troy oz to grams: grams = troy oz × 31.1034768

  • Grams to troy oz: troy oz = grams / 31.1034768
  • Troy oz to grams: grams = troy oz × 31.1034768
  • Exact definition: 1 troy oz = 31.1034768 g

How To Convert Grams to Troy Ounces in 3 Steps

Inputs

  • Direction: grams to troy ounces, or troy ounces to grams
  • Value: the mass to convert in the input unit

Steps

  1. Select the conversion direction (grams to troy oz, or troy oz to grams).
  2. Enter the value in the selected input unit.
  3. Read the converted value.

Grams to Troy Ounces Worked Example: Gold Bar and Coin

Converting 1,000 g gold bar, 1 troy oz coin, and 15 g silver nugget.

  1. 1,000 g gold bar: 1,000 / 31.1034768 = 32.1507 troy oz.
  2. 1 troy oz coin: 1 × 31.1034768 = 31.1035 g.
  3. 15 g silver nugget: 15 / 31.1034768 = 0.4823 troy oz.

1 kg gold = 32.1507 t oz; 1 t oz = 31.1035 g; 15 g silver = 0.4823 t oz.

Troy Ounce vs Avoirdupois Ounce: When To Use Which

Use troy ounces when buying, selling, or weighing precious metals (gold, silver, platinum, palladium) or gemstones. Spot prices on exchanges are all quoted per troy ounce. Use avoirdupois ounces for everyday goods.

Assumptions

  • The conversion factor 1 troy oz = 31.1034768 g is exact.
  • The calculator converts mass only; it does not compute monetary value or purity.
  • Both grams and troy ounces measure mass.

Limitations

  • Does not convert to avoirdupois ounces, pounds, or other weight units.
  • Does not calculate monetary value.
  • Does not account for metal purity (fineness).

In Practice

When calculating precious metal value, the formula is: value = mass (g) / 31.1034768 × spot price ($/troy oz). A common shortcut is to multiply grams by 0.03215 (the reciprocal of 31.1034768) to get troy ounces. For large transactions, use the full exact factor to avoid compounding rounding errors. Bullion dealers and refiners use the full precision factor in their calculations.

Related Guides

Frequently Asked Questions: Grams to Troy Ounces Tool

Why do precious metals use troy ounces instead of regular ounces?

The troy weight system dates to medieval trade in Troyes, France, and has been used for precious metals and gemstones for centuries. When commodity exchanges standardised precious metal pricing in the 19th and 20th centuries, the troy ounce was the established unit.

How different is a troy ounce from a regular ounce?

One troy ounce = 31.1034768 g. One avoirdupois ounce = 28.3495 g. A troy ounce is about 9.7% heavier than an avoirdupois ounce. If you buy 1 ounce of gold at a spot price quoted per troy oz, you receive 31.10 g of gold, not 28.35 g.

What is the exact value of 1 troy ounce in grams?

1 troy ounce = 31.1034768 grams exactly by definition. This is not a rounded approximation. One troy pound = 12 troy ounces = 373.2417216 g.

Is the troy ounce used for anything other than precious metals?

Historically, the troy system was used for all precious metals and gemstones. Today its main use is precious metals (gold, silver, platinum, palladium) and pharmaceutical active substances. Gemstone weight is measured in carats (1 carat = 0.2 g).

How do I convert troy ounces to grams on a regular calculator?

Multiply the number of troy ounces by 31.1034768. For example, 2.5 troy oz × 31.1034768 = 77.759 g. To go from grams to troy ounces, divide by 31.1034768, or multiply by 0.032151.

Sources

Last updated: . Reviewed for accuracy against the formula shown above.