How Many Grams in a Troy Ounce?
There are exactly 31.1035 grams in one troy ounce. This applies to all precious metals — gold, silver, platinum, and palladium.
The troy ounce is the universal unit for precious metals pricing worldwide. It differs from the everyday avoirdupois ounce. Live gold and silver prices per gram are shown below.
Troy Ounce ↔ Gram Conversion Table
Exact mathematical conversions based on 1 troy oz = 31.1034768 grams.
| Troy Ounces | Grams | Kilograms | Pennyweight (dwt) | Regular Oz |
|---|---|---|---|---|
| 0.1 oz t | 3.1103 g | 0.003110 kg | 2.000 dwt | 0.1097 oz |
| 0.5 oz t | 15.552 g | 0.01555 kg | 10.00 dwt | 0.5486 oz |
| 1 oz t | 31.1035 g | 0.03110 kg | 20.00 dwt | 1.0971 oz |
| 2 oz t | 62.207 g | 0.06221 kg | 40.00 dwt | 2.1943 oz |
| 5 oz t | 155.52 g | 0.15552 kg | 100.0 dwt | 5.4857 oz |
| 10 oz t | 311.03 g | 0.31103 kg | 200.0 dwt | 10.971 oz |
| 32.1507 oz t | 1,000 g | 1.000 kg | 643.0 dwt | 35.274 oz |
| 100 oz t | 3,110 g | 3.110 kg | 2,000 dwt | 109.71 oz |
| 400 oz t | 12,441 g | 12.441 kg | 8,000 dwt | 438.9 oz |
Gram to Troy Ounce — with Live Gold & Silver Values
| Grams | Troy Ounces | Pennyweight | Gold Value (USD) | Silver Value (USD) |
|---|---|---|---|---|
| 0.1 g | 0.003215 oz t | 0.0643 dwt | — | — |
| 0.5 g | 0.01607 oz t | 0.3215 dwt | — | — |
| 1 g | 0.03215 oz t | 0.6430 dwt | — | — |
| 2 g | 0.06430 oz t | 1.286 dwt | — | — |
| 3 g | 0.09645 oz t | 1.929 dwt | — | — |
| 5 g | 0.1607 oz t | 3.215 dwt | — | — |
| 10 g | 0.3215 oz t | 6.430 dwt | — | — |
| 31.1035 g | 1.000 oz t | 20.00 dwt | — | — |
| 100 g | 3.215 oz t | 64.30 dwt | — | — |
Weight Converter — Any Amount
Convert any precious metals weight and see the live USD value.
Troy Ounce Explained
What Is a Troy Ounce?
The troy ounce is the standard unit of mass for weighing precious metals globally. It originates from the troy weights system used in medieval European trade, likely from the city of Troyes, France. One troy ounce equals exactly 31.1034768 grams, commonly rounded to 31.1035 g.
Troy Ounce vs Regular Ounce
| Unit | Grams | Used For |
|---|---|---|
| Troy Ounce (oz t) | 31.1035 g | Gold, silver, platinum, palladium |
| Avoirdupois Ounce (oz) | 28.3495 g | Everyday goods, food, general trade |
| Apothecary Ounce | 31.1035 g | Historical pharmacy (same as troy) |
A gold bar labelled "1 oz" at any bullion dealer is always a troy ounce (31.1035 g), not a regular ounce (28.3495 g). This difference of 2.75 grams matters enormously when buying or selling gold.
Troy Ounce vs Pennyweight (dwt)
US jewellers often use pennyweight (dwt). There are exactly 20 pennyweights in one troy ounce, and 1 dwt = 1.55517 grams. To compare a dealer's dwt price to a per-gram price: multiply by 1.55517. To compare to a per-oz price: multiply by 20.
How to Convert Grams to Troy Ounces
- Weigh your gold or silver item in grams on a precise scale.
- Divide the weight in grams by 31.1035 to get troy ounces.
- Multiply by the live spot price to get the raw melt value.
- For alloyed gold (14K, 10K, 18K), multiply by the purity factor (0.5833, 0.4167, 0.75).
Example: 8.5g of 14K gold. Troy oz: 8.5 ÷ 31.1035 = 0.2733 oz t. Value: 0.2733 × spot × 0.5833. Use our 14K Gold Calculator for an instant live result.