The Troy Weight Calculator converts between units in the troy weight system, the system used for precious metals such as gold and silver. Enter a value in troy ounces, pennyweight, grains or troy pounds, and the tool returns the equivalent in any other troy unit, with the multiply or divide step shown.
Troy weight looks similar to the everyday avoirdupois system at first glance, sharing unit names like "ounce" and "pound," but the actual weights behind those names differ. A troy ounce is heavier than an avoirdupois ounce, while a troy pound is lighter than an avoirdupois pound, which makes troy weight a common source of confusion for anyone new to precious-metal pricing.
Convert between troy units
The troy system defines fixed ratios between its units: 20 pennyweight to a troy ounce, 12 troy ounces to a troy pound, and 480 grains to a troy ounce.
1 troy ounce = 20 pennyweight = 480 grains = 31.1034768 grams
1 troy pound = 12 troy ounces = 5,760 grains = 373.2417216 gramsWorked example: convert 3 troy ounces to pennyweight.
1. Multiply by 20. 3 × 20 = 60 pennyweight.
Convert troy ounces to grams
Precious-metal prices are quoted per troy ounce worldwide, so converting to grams is a common need when comparing a quoted price against a metric scale reading.
grams = troy ounces × 31.1034768Worked example: convert 2 troy ounces to grams.
1. Multiply by 31.1034768. 2 × 31.1034768 ≈ 62.21 grams.
That figure, about 62.2 grams for two troy ounces, is noticeably more than the 56.7 grams that two avoirdupois ounces would weigh, since the troy ounce is roughly ten percent heavier.
Convert troy ounces to pennyweight
Pennyweight, abbreviated dwt, is a smaller troy unit still used by jewelers for weighing gold and gemstone settings.
pennyweight = troy ounces × 20Worked example: convert 1.5 troy ounces to pennyweight.
1. Multiply by 20. 1.5 × 20 = 30 pennyweight.
Pennyweight itself breaks down further into 24 grains, so a jeweler working with very small gold quantities may move between pennyweight and grains rather than ounces at all.
Convert troy pounds to troy ounces
A troy pound contains only 12 troy ounces, unlike the avoirdupois pound's 16 ounces, which is one of the clearest differences between the two systems.
troy ounces = troy pounds × 12Worked example: convert 2 troy pounds to troy ounces.
1. Multiply by 12. 2 × 12 = 24 troy ounces.
Despite having fewer, heavier ounces per pound, the troy pound itself, at about 373.24 grams, is still lighter overall than the avoirdupois pound, at about 453.59 grams, because the ounce-count difference (12 versus 16) outweighs the per-ounce weight difference.
Check common troy conversions
| Troy ounces | Pennyweight | Grains | Grams |
|---|---|---|---|
| 1 oz t | 20 dwt | 480 gr | 31.10 g |
| 5 oz t | 100 dwt | 2,400 gr | 155.52 g |
| 12 oz t | 240 dwt (1 troy lb) | 5,760 gr | 373.24 g |
The 12-troy-ounce row lines up exactly with one troy pound, confirming the fixed ratio that defines the troy pound in the first place.
Avoid mixing troy and avoirdupois ounces
The single most common troy-weight mistake is treating "an ounce" as always meaning the same thing. A troy ounce (31.1034768 g) is about 9.7 percent heavier than an avoirdupois ounce (28.349523125 g), so pricing an item by weight using the wrong ounce definition produces a real, consistent error rather than a rounding issue.
Precious-metal markets, coin dealers and bullion listings use troy ounces specifically; grocery scales, postal weights and most other everyday measurements use avoirdupois ounces.
Convert pennyweight back to troy ounces
Reversing the troy-ounce-to-pennyweight relationship means dividing by 20 instead of multiplying.
troy ounces = pennyweight ÷ 20Worked example: convert 90 pennyweight to troy ounces.
1. Divide by 20. 90 ÷ 20 = 4.5 oz t.
So 90 pennyweight equals exactly 4.5 troy ounces, the same 20-pennyweight-per-troy-ounce ratio used earlier on this page, applied as a division rather than a multiplication.
Convert grains back to troy ounces
Grains are the smallest common troy unit, so converting back to troy ounces means dividing by 480.
troy ounces = grains ÷ 480Worked example: convert 960 grains to troy ounces.
1. Divide by 480. 960 ÷ 480 = 2 oz t.
So 960 grains equals exactly 2 troy ounces, confirming the same 480-grains-per-troy-ounce ratio used throughout this page, whether converting forward from ounces or back from grains.
Frequently asked questions
How many grams are in a troy ounce?
One troy ounce equals exactly 31.1034768 grams, heavier than the 28.349523125 grams in an avoirdupois ounce.
How many troy ounces are in a troy pound?
12 troy ounces make one troy pound, fewer than the 16 avoirdupois ounces in an avoirdupois pound.
What is a pennyweight?
A pennyweight (dwt) is 1/20 of a troy ounce, or 24 grains, and is commonly used by jewelers for weighing gold and gemstone mountings.
Is a troy pound heavier or lighter than a regular pound?
A troy pound, at about 373.24 grams, is lighter than an avoirdupois pound, at about 453.59 grams, even though a troy ounce is individually heavier than an avoirdupois ounce.
Why does gold get priced in troy ounces?
Troy ounces have been the standard unit for precious-metal trading for centuries, and the convention has persisted globally even as most other everyday weight measurements use avoirdupois or metric units.
How many grains are in a troy ounce?
480 grains make one troy ounce, compared with 437.5 grains in an avoirdupois ounce, since the grain itself is defined the same way across both systems.
Can this calculator convert troy weight into kilograms?
Yes. Since 1 troy ounce equals exactly 31.1034768 grams, any troy figure converts directly to grams or kilograms using that fixed factor.
Summary
The troy system links troy ounces, pennyweight, grains and troy pounds through fixed ratios: 20 pennyweight and 480 grains per troy ounce, and 12 troy ounces per troy pound. A troy ounce, at 31.1034768 grams, is heavier than an avoirdupois ounce, while a troy pound, at about 373.24 grams, is lighter than an avoirdupois pound.
Precious-metal weights should always specify troy explicitly, since mixing troy and avoirdupois ounces produces a consistent, meaningful error rather than a rounding difference.