Ounces to Grams Converter
1 oz = 28.3495 g. Troy ounces are heavier — switch below.
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Gold, silver and platinum are weighed in troy ounces, which are about 10 % heavier than ordinary ounces.
28.35 grams — unless it is gold
An ordinary ounce is exactly 28.349523125 grams. Cooks round it to 28, which is 1.2 % light and perfectly fine for a recipe.
1 oz = 28.349523125 g 1 troy oz = 31.1034768 g
The exception is precious metals. Gold, silver and platinum are weighed in troy ounces, which are 31.1035 grams — about 10 % heavier. A gold price quoted "per ounce" always means troy.
Using the wrong ounce on a bullion calculation is a 10 % error, which at current gold prices is a serious amount of money. The switch below picks between them.
The ounce
A sixteenth of a pound, and exactly 28.349523125 grams. This is the avoirdupois ounce, the one used for food and everyday goods.
There is another. The troy ounce, used for gold, silver and platinum, is 31.1034768 grams — about 10 % heavier. A price quoted per ounce of gold always means a troy ounce.
And a fluid ounce is something else again: a measure of volume, not mass.
The gram
A thousandth of a kilogram, and the everyday unit for food, ingredients and small objects. A paperclip is about a gram; a slice of bread around 40.
Oddly, the gram is not the SI base unit even though it carries the prefixes — the kilogram is. That makes the kilogram the only SI base unit with a prefix built into its name.
The working, step by step
Every line updates with whatever you type above. The point is the method, which is the same for any pair of units in this family.
The same quantity, two different numbers
One physical amount, read off two scales. The tick marks do not line up, and the gap between them is the conversion factor made visible.
How much is that?
A number is easier to judge next to something familiar.
Your turn
Reading a method and being able to use it are different things. Answer within half a per cent and it counts as correct.
Score: 0 of 0
How to use this converter
- Type into either box. The other side updates as you go; there is no button to press.
- Swap the direction with the button between the boxes, carrying your value across.
- Set the decimals if the default is more or less precision than you need.
- Copy the answer with its unit, ready to paste.
- Use the shortcut buttons for the values that come up most often.
- Share the result. The address bar tracks what you type, so the link you copy opens on the same number.
Common uses and tips
Where mass conversions come up
- Cooking, where recipes give grams in most of the world and ounces in the United States.
- Body weight, in kilograms nearly everywhere, pounds in America, and stones and pounds in Britain and Ireland.
- Shipping and postage, priced by weight bands that differ between carriers and countries.
- Medicine, where doses are in milligrams or micrograms and often scaled by body weight in kilograms.
- Precious metals, which use the troy ounce rather than the ordinary one.
The trap: which ounce, and which ton
Two units on this page have more than one meaning.
Ounces. The everyday avoirdupois ounce is 28.3495 grams. The troy ounce, used for gold, silver and platinum, is 31.1035 grams — about 10 % heavier. A gold price quoted per ounce always means troy. Using the wrong one on a bullion calculation is a ten per cent error.
Tons. A metric tonne is 1,000 kg. A US short ton is 2,000 lb, or 907 kg. A UK long ton is 2,240 lb, or 1,016 kg. The spread between the smallest and largest is over 12 %, which on a freight invoice is real money.
Mass is not weight
Strictly, everything on this page measures mass — how much matter there is. Weight is the force gravity exerts on that mass, and is properly measured in newtons.
Your mass is the same on the Moon; your weight is about a sixth. In everyday use nobody makes the distinction, and bathroom scales, baggage counters and recipes all use the two words interchangeably. It only matters in physics.
Numbers worth carrying
- 1 kg = 2.20462 lb, and 1 lb = 0.45359237 kg exactly.
- 1 oz = 28.3495 g. For cooking, 28 is close enough.
- 16 ounces to the pound, 14 pounds to the stone.
- Weigh, do not measure, for baking. A cup of flour varies by up to 20 % depending how it was packed; 120 g is 120 g.
Values people look up most
Each one opens the converter with the number already in it.
- 0.5 oz to g
- 1 oz to g
- 1.5 oz to g
- 2 oz to g
- 3 oz to g
- 4 oz to g
- 5 oz to g
- 6 oz to g
- 8 oz to g
- 10 oz to g
- 12 oz to g
- 14 oz to g
- 16 oz to g
- 20 oz to g
- 24 oz to g
- 32 oz to g
Quick reference
Using ordinary avoirdupois ounces of 28.3495 g.
| Ounces | Grams |
|---|---|
| 1 oz | 28.349523 g |
| 2 oz | 56.699046 g |
| 4 oz | 113.398093 g |
| 8 oz | 226.796185 g |
| 12 oz | 340.194277 g |
| 16 oz | 453.59237 g |
| 32 oz | 907.18474 g |
Questions people ask
How many grams in an ounce?
28.3495 g for an ordinary ounce, 31.1035 g for a troy ounce.
What is a troy ounce?
The unit used for gold, silver and platinum. It is about 10 % heavier than the everyday avoirdupois ounce.
Can I use 28 g?
For cooking, yes. It is 1.2 % light.
Is a fluid ounce the same?
No. A fluid ounce measures volume, not mass.