Grams, pennyweights and troy ounces: convert gold weight and see the value
In short
A troy ounce is 31.1035 grams; the ounce on a kitchen scale is 28.3495 grams, about 10% less. A pennyweight (dwt) is 1.55517 grams, one twentieth of a troy ounce. Gold is priced per troy ounce, so today's $4,408.50 spot is $141.74 per gram and $220.42 per pennyweight. Enter any weight below to convert it and price it.
- grams
- pennyweight (dwt)
- troy ounces
- ounces (avoirdupois)
- kilograms
- grains
- 24k (99.9% gold)
- 22k (91.6% gold)
- 21k (87.5% gold)
- 18k (75% gold)
- 14k (58.5% gold)
- 12k (50% gold)
- 10k (41.7% gold)
- 9k (37.5% gold)
| grams | 31.1035 |
|---|---|
| pennyweight (dwt) | 20.00006 |
| troy ounces | 1 |
| ounces (avoirdupois) | 1.09714 |
| kilograms | 0.0311 |
| grains | 480.00036 |
Spot $4,408.50/oz t = $141.74/g · gold-api.com · 2026-09-04
The three ounces and why buyers like pennyweights
The troy system survives only in precious metals. One troy pound is 12 troy ounces, one troy ounce is 20 pennyweights, one pennyweight is 24 grains, and the grain is the one unit shared with the everyday avoirdupois system: 480 grains make a troy ounce, 437.5 make a regular ounce. That is the whole difference, and it is why a bullion coin stamped one ounce weighs more than an ounce of flour.
Many American gold buyers still quote in pennyweights. There is nothing wrong with the unit, but a price per pennyweight sounds larger than a price per gram for the same metal, and most sellers do not carry the 1.555 conversion in their head. Ask for the quote per gram; if a buyer will only quote per dwt, divide by 1.55517 before comparing.
Conversion table
| Unit | Grams | Pennyweight | Troy oz | Ounce (avdp) |
|---|---|---|---|---|
| 1 gram | 1 | 0.6430 | 0.03215 | 0.03527 |
| 1 pennyweight | 1.5552 | 1 | 0.05 | 0.05486 |
| 1 troy ounce | 31.1035 | 20 | 1 | 1.0971 |
| 1 ounce (avdp) | 28.3495 | 18.229 | 0.9115 | 1 |
| 1 grain | 0.0648 | 0.04167 | 0.002083 | 0.002286 |
| 1 kilogram | 1000 | 643.01 | 32.151 | 35.274 |
Step-by-step conversions
Grams to troy ounces
Divide by 31.1035. A 46.7 g chain is 46.7 ÷ 31.1035 = 1.50 troy ounces. Its melt value in 14k is 1.50 × 0.585 × $4,408.50 = $3,872.17, the same answer as 46.7 × 0.585 × $141.74.
Troy ounces to grams
Multiply by 31.1035. A one ounce coin is 31.1 g; a tenth-ounce coin is 3.11 g.
Pennyweights to grams
Multiply by 1.55517. A buyer's quote of 12 dwt is 18.66 g. A quote of $103.16 per dwt for 14k is $66.33 per gram, which you can then compare with the melt figure of $82.92.
Grams to pennyweights
Divide by 1.55517, or multiply by 0.643. A 10 g ring is 6.43 dwt.
Kitchen ounces to grams
Multiply by 28.35, not 31.1: a scale set to ounces reads avoirdupois. A ring showing 0.21 oz on a kitchen scale is 5.95 g, not 6.53 g.
Weight and purity are two different things
Weight is how much metal there is; purity is how much of it is gold. Value needs both, and confusing them is the most common mistake in a quote. Ten grams of 14k is 10 g of metal and 5.85 g of gold; a buyer paying "per gram of gold" and one paying "per gram of 14k" are quoting numbers that differ by 41.5%, and both are legitimate as long as you know which one you are hearing. The gold content calculator does the purity step; this page does the weight step; the price page puts them together.
Spot is always per troy ounce
Every gold price you see in the news, on a dealer's board or in a buyer's window is dollars per troy ounce of pure gold, or a conversion of it. To turn it into a price per gram of your karat: divide by 31.1035, then multiply by the gold fraction. Spot $4,408.50 ÷ 31.1035 = $141.74 per gram pure, × 0.585 = $82.92 per gram of 14k. Any quote that cannot be traced back to spot by that arithmetic is a quote to walk away from.
Buying and selling by weight
Buying: bullion is sold by troy ounce and gram at a small premium over spot, and the premium per gram is lower on larger bars; jewelry is sold by the piece, and dividing its price by its weight in grams tells you how many times melt you are paying, which is the fairest single measure of a jewelry price. Selling: insist on grams, insist on karat-by-karat weighing, and insist on seeing the scale. A scale that reads in dwt is not dishonest, but a seller who does not convert is at a disadvantage the buyer did not create and will not correct.
Weighing gold at home
A pocket scale that reads to 0.01 g costs less than a gram of 10k gold and is the single most useful tool a seller can own. Weigh on a hard level surface, tare a small dish first, and weigh each karat separately. Digital kitchen scales that read whole grams are fine above about 20 grams; below that, rounding to the nearest gram can be a 5% error, which is more than the spread between two honest buyers.
Questions people ask
How many grams are in a pennyweight of gold?
1.55517 g, and twenty pennyweights make a troy ounce. The unit is medieval English, the weight of a silver penny, and the jewelry trade kept it after everyone else moved to grams. A buyer quoting $128.95 per dwt for 14k is quoting $82.92 per gram; divide by 1.555 before comparing.
What is the difference between a troy ounce and a regular ounce?
A troy ounce is 31.1035 g, a regular avoirdupois ounce 28.3495 g, so troy is 9.7% heavier. Everything priced as precious metal uses troy. A one ounce gold coin on a kitchen scale reads 1.097 oz, which alarms people who do not know the difference and reassures those who do.
How accurate does my scale need to be?
To 0.1 g for anything under 20 grams, to 0.01 g if you sell small pieces often. A scale that rounds to whole grams turns a 3.4 g earring into 3 g, a 12% error worth about $33.17 in 14k, which is more than the spread between two honest buyers. Pocket scales reading 0.01 g cost less than a gram of 10k.
How much is a pennyweight of 14k gold worth?
$128.95 at today's spot: 1.55517 g × 58.5% × $141.74. A refiner might offer 90% of that, a pawn shop half; the percentage is what to compare, because the dollar figure changes every day and the percentage does not.
Why do jewelers use dwt?
Habit from the troy system, and because a price per dwt looks 55% bigger than the same price per gram. Some refiners have switched to grams; many local buyers have not. The unit is not dishonest; relying on the customer not converting is.
What is a grain?
The smallest troy unit, 0.0648 g, and the one shared with the everyday system: 480 grains make a troy ounce, 437.5 a regular ounce. You meet it on old bullion and in ammunition, not in a jewelry store, but it is why 24k coins are sometimes listed as 480 grains.