1 troy ounce (ozt) = exactly 31.1034768 grams. An ordinary ounce (oz) is 28.349523125 grams, so the units are not interchangeable.
Important: “oz” and “ozt” are different. Precious-metal quotations conventionally use the troy ounce (ozt). Many postal, kitchen and bathroom scales use the ordinary avoirdupois ounce (oz).
A unit conversion preserves the weight you entered. Converting a 925 object to troy ounces does not turn its gross weight into fine-silver weight. Apply purity separately in the silver calculator. On a scale, gr means grains, not grams; verify ambiguous labels in the scale manual.
Precious-metal weight conversion table
| Unit | Common label | Grams | Troy ounces |
|---|---|---|---|
| 1 gram | g | 1 | 0.0321507466 |
| 1 kilogram | kg | 1,000 | 32.1507466 |
| 1 troy ounce | ozt; sometimes oz t | 31.1034768 | 1 |
| 1 ordinary ounce | oz; avoirdupois | 28.349523125 | 0.911458333 |
| 1 pennyweight | dwt | 1.55517384 | 0.05 |
| 1 grain | gr | 0.06479891 | 0.002083333 |
| 1 troy pound | troy lb; confirm 12 ozt | 373.2417216 | 12 |
| 1 avoirdupois pound | lb; ordinary pound | 453.59237 | 14.5833333 |
How the converter works
Every supported unit is first converted to grams, then from grams to the requested unit:
result = amount × grams per source unit ÷ grams per target unitThe displayed result is rounded for readability. Calculations use the constants shown in the table. This converter changes units only; it does not change purity or calculate metal value.
Troy ounce versus ordinary ounce
The troy system is traditionally used for precious metals. A troy ounce is about 9.7% heavier than an ordinary ounce. However, a troy pound has only 12 troy ounces, while an avoirdupois pound has 16 ordinary ounces. The converter labels ordinary pounds and troy pounds separately; choose the unit actually used by the source.
What is a pennyweight?
A pennyweight, abbreviated dwt, is one twentieth of a troy ounce. It equals 24 grains or 1.55517384 grams. Jewelry and precious-metal buyers sometimes quote weights or prices in pennyweights, so confirm the unit before comparing offers.
Useful conversion examples
- 10 troy ounces = 311.034768 grams.
- 100 grams = approximately 3.21507466 troy ounces.
- 1 gram = approximately 0.0321507466 troy ounce.
- One tenth of a troy ounce = 3.11034768 grams.
- 20 pennyweights = 1 troy ounce.
- 480 grains = 1 troy ounce.
- 1 ordinary pound = approximately 14.5833333 troy ounces.
Frequently asked questions
How many grams are in a troy ounce?
Exactly 31.1034768 grams.
How many pennyweights are in a troy ounce?
Exactly 20 pennyweights.
Do purity and karat affect weight conversion?
No. A unit conversion preserves gross weight. Purity is applied separately when calculating fine-metal content. For that, use the gold or silver value calculator.
Can I use this converter for copper?
Yes. Weight units themselves are independent of the metal. The copper calculator additionally converts a manual per-pound reference into contained value.
What do ozt and dwt mean on a scale?
Ozt, oz t and toz identify a troy ounce: 31.1034768 g. Dwt means pennyweight: 1.55517384 g. There are 20 pennyweights in one troy ounce, but about 18.22917 in one ordinary ounce. Check the scale mode before converting.
A troy pound is 12 troy ounces (373.2417216 g). An ordinary pound is 16 ordinary ounces (453.59237 g). These weight conversions are the same for gold, silver and other materials; a value calculation also needs purity and a dated price. Constants follow NIST conversion factors.