Weight converter
Grams to ounces
Grams
100 g
Ounces
0 lb 3.53 oz
The word “ounce” covers two completely different units. The avoirdupois ounce (28.35 g) is what food labels, recipes, and postal scales use. The troy ounce (31.10 g) is what gold and silver markets use. They share a name but differ by nearly 10%. Use the wrong one and a food calculation is slightly off; use the wrong one for precious metals and the error runs to hundreds of dollars per kilogram.
The converter above uses the avoirdupois ounce, the standard for food and everyday weight. It returns the decimal ounce value plus the full pounds-and-ounces breakdown in one result. Below, you will find the formula, a reference table, real-world use cases, and the avoirdupois vs troy distinction in full.
Table of Contents
- How to Use This Converter
- The Grams to Ounces Formula
- Avoirdupois vs Troy Ounce
- Real-World Uses
- Quick Reference Conversion Table
- Common Mistakes to Avoid
- Frequently Asked Questions
How to Use This Converter
The tool at the top of this page works in two steps.
- Enter a value in grams. Type any positive number. Decimals work: 28.35, 100, 453.6. The result updates as you type, and numbers stay fully visible as you add digits.
- Read both outputs. The converter returns the decimal ounce value (e.g., 3.5274 oz) and the full pounds-and-ounces breakdown (e.g., 0 lb 3.53 oz) at the same time. You do not need to run two separate calculations.
The preset cards below the input cover the four most common reference values: 28.35 g (exactly 1 oz), 100 g, 250 g, and 1000 g (1 kg). These cover most cooking and baking searches. Tap any preset and the result updates instantly.
The Grams to Ounces Formula
One conversion factor covers all everyday use.
Grams to ounces (avoirdupois):
ounces = grams × 0.035274
Or: ounces = grams ÷ 28.3495
Both give the same result. The first (multiplying) is faster on a calculator. The second (dividing) is easier to verify mentally.
Example: 250 grams × 0.035274 = 8.8185 oz. Rounded for everyday use: 8.82 oz.
To reverse (ounces back to grams):
grams = ounces × 28.3495
A quick mental shortcut: 100 grams is roughly 3.5 ounces. For a rough estimate, multiply the number of hundreds by 3.5. So 400 grams is approximately 14 ounces (exact: 14.11 oz). This works within about 0.5% for everyday cooking.
The exact conversion factor is defined by the 1959 International Yard and Pound Agreement, which set 1 avoirdupois ounce as exactly 28.349523125 grams. The relationship has not changed since.
Avoirdupois vs Troy Ounce: The Difference That Costs Money
Most people encounter only one type of ounce in daily life. Two actually exist, and mixing them up in a precious metals transaction produces a significant error.
The avoirdupois ounce (28.3495 g)
This is the standard ounce for food, groceries, postal packages, kitchen scales, and body weight in the United States. When a recipe calls for 4 oz of chocolate, when a cereal box lists a serving as 1 oz, or when a courier charges by the ounce, all of these refer to the avoirdupois ounce. The name comes from the Old French phrase “aveir de pois,” meaning “goods of weight.” There are 16 avoirdupois ounces in one avoirdupois pound (453.59 g).
The troy ounce (31.1035 g)
This is the global standard for trading precious metals: gold, silver, platinum, and palladium. One troy ounce equals 31.1035 grams, about 9.7% heavier than the avoirdupois ounce. The troy system originated from the trade fairs of Troyes, France, in the Middle Ages, and was adopted by the US Mint in 1828. Today, every gold and silver price quoted on a commodity market, every bullion coin specification, and every refinery transaction uses troy ounces.
The difference is significant in practice. If you buy a 100-ounce gold bar and assume avoirdupois ounces, you would calculate 2,834.95 grams. The bar actually contains 3,110.35 grams (troy). At current gold prices, that 275-gram gap represents thousands of dollars of misvalued metal.
| Avoirdupois Ounce | Troy Ounce | |
|---|---|---|
| Grams | 28.3495 g | 31.1035 g |
| Ounces per pound | 16 oz = 1 lb | 12 oz = 1 troy lb |
| Used for | Food, postal, everyday commerce | Gold, silver, platinum, palladium |
| Symbol | oz | oz t or ozt |
| Heavier? | No | Yes, by ~10% |
Note the counterintuitive result: a troy ounce is heavier than an avoirdupois ounce, but a troy pound is lighter than an avoirdupois pound. This is because a troy pound contains 12 troy ounces (373.24 g), while an avoirdupois pound contains 16 avoirdupois ounces (453.59 g).
This converter uses the avoirdupois ounce. If you work with precious metals, multiply your gram figure by 0.032151 to get troy ounces instead.
Real-World Uses: When You Need This Conversion
Cooking and Baking International Recipes
Recipes from the UK, Australia, Europe, and most professional culinary sources use grams. US recipes use ounces and cups. When a British bread recipe calls for 500 g of flour, that is 17.64 oz. A French pastry recipe using 85 g of butter needs 3 oz. Converting before you start means you do not stop mid-recipe to calculate.
Baking is less forgiving than general cooking. The ratio of flour, fat, liquid, and leavening determines texture, rise, and crumb. A 5-gram error in flour at 250 g is 2%, which is within acceptable range. At 50 g of baking powder, a 5-gram error is 10%, enough to affect leavening noticeably. Use precise conversion rather than rounding to the nearest ounce.
Reading Nutrition Labels
US nutrition labels list serving sizes in both ounces and grams. The FDA requires manufacturers to express 1 oz as 28 grams on food packaging. When comparing products from different countries or following a diet plan that uses grams while your tracking app shows ounces, you need to convert accurately. A serving of 170 g of chicken breast is 6 oz; a 30 g serving of almonds is 1.06 oz. Small rounding differences change calorie and macronutrient totals in diet tracking.
Precious Metals and Jewelry
Gold, silver, platinum, and palladium are priced in troy ounces globally. A gram weight of gold converts to troy ounces (not avoirdupois) for pricing purposes. 10 grams of gold equals 0.3215 troy ounces. If a jeweler quotes a ring at “2 oz of gold,” that means troy ounces: 62.21 grams, not the 56.70 grams an avoirdupois conversion would give.
Postal and Shipping Weights
US postal rates are determined by weight in ounces for lightweight items. A letter weighing 35 grams is 1.23 oz, which falls into the first-class letter weight bracket. International shipping often uses grams in the sender country and ounces at the US destination, making conversion necessary for accurate cost estimates before dispatch.
Pharmaceutical and Supplement Dosing
Supplement packaging in some markets lists dose sizes in grams or milligrams, while others list in ounces. Protein powder scoops, pre-workout servings, and herbal supplement amounts all cross between systems depending on the brand’s country of origin. 30 g of protein powder is 1.06 oz; 5 g of creatine is 0.18 oz.
Fitness and Portion Control
Nutritionists and coaches who work with clients across countries deal with both systems daily. A diet plan recommending 75 g of protein per meal gives a US client a figure their kitchen scale in ounces must match: 2.65 oz. A bodybuilder weighing 180 g of chicken at lunch needs to record 6.35 oz in an imperial-based tracking app.
Manufacturing and Retail Packaging
Products manufactured in metric countries and exported to the US require dual weight labeling. A 250 g jar of jam needs to show 8.82 oz on the US import label. Manufacturers and importers run these conversions across entire product lines when preparing for US retail distribution.
Quick Reference Conversion Table
| Grams (g) | Ounces (oz) | Pounds and Ounces |
|---|---|---|
| 1 | 0.0353 | 0 lb 0.04 oz |
| 5 | 0.1764 | 0 lb 0.18 oz |
| 10 | 0.3527 | 0 lb 0.35 oz |
| 25 | 0.8818 | 0 lb 0.88 oz |
| 28.35 | 1.0000 | 0 lb 1.00 oz |
| 50 | 1.7637 | 0 lb 1.76 oz |
| 100 | 3.5274 | 0 lb 3.53 oz |
| 150 | 5.2911 | 0 lb 5.29 oz |
| 200 | 7.0548 | 0 lb 7.05 oz |
| 250 | 8.8185 | 0 lb 8.82 oz |
| 300 | 10.582 | 0 lb 10.58 oz |
| 400 | 14.110 | 0 lb 14.11 oz |
| 453.59 | 16.000 | 1 lb 0.00 oz |
| 500 | 17.637 | 1 lb 1.64 oz |
| 750 | 26.455 | 1 lb 10.46 oz |
| 1000 | 35.274 | 2 lb 3.27 oz |
For values not in the table, use the converter at the top of the page or apply: ounces = grams × 0.035274.
Common Mistakes to Avoid
Using the troy conversion for everyday weight
Searching “grams to ounces” sometimes returns results referencing the troy ounce (31.1035 g) because precious metals sites rank for this query. If your context is food, cooking, shipping, or body weight, you need the avoirdupois ounce (28.3495 g). The difference is about 2.75 grams per ounce. At 500 grams, using the troy factor gives 16.08 oz instead of the correct 17.64 oz, a gap of 1.56 oz.
Rounding 28.35 to 28 per ounce
Using 28 grams per ounce instead of 28.3495 introduces a 1.2% error per ounce. At 1 oz it is 0.35 g, which is negligible. At 16 oz (1 lb), the error grows to 5.6 g. For food labeling, the FDA allows 28 g as the rounded value for a 1 oz serving size, but this is a regulatory rounding rule, not an accurate conversion constant. For weight conversion calculations, use 28.3495 or divide by the full factor.
Confusing weight ounces with fluid ounces
A fluid ounce (fl oz) measures volume, not mass. 1 fl oz of water weighs approximately 29.57 grams. 1 weight ounce (oz) is 28.35 grams. They are close but not equal, and for liquids other than water, they differ significantly: 1 fl oz of honey weighs about 43 grams because honey is denser than water. When a recipe uses “oz” for a liquid, check whether it means fluid ounces (volume) or weight ounces (mass). Most liquid ingredients in US recipes mean fluid ounces; most solid ingredients mean weight ounces.
Assuming metric recipes are less precise
A UK recipe listing 225 g of flour is more precise than a US recipe calling for 2 cups. Cups measure volume, not weight, so a cup of flour varies by 20% or more depending on how it is scooped. Professional bakers weigh ingredients in grams for consistency. Converting a gram-based recipe to ounces and then measuring by volume introduces the same imprecision that grams were designed to remove.
Forgetting to convert the full ingredient list
When adapting a recipe from grams to ounces, convert every ingredient before starting. Stopping to convert mid-preparation while hands are covered in dough or while heat is applied causes errors. Pre-calculate all conversions, write them down, and work from the converted list.
Frequently Asked Questions
How many ounces is 1 gram?
1 gram equals 0.035274 ounces (avoirdupois). Multiply any gram value by 0.035274 to get ounces, or divide by 28.3495 for the same result.
What is the formula to convert grams to ounces?
Multiply the number of grams by 0.035274. For example, 100 grams times 0.035274 equals 3.5274 ounces. You can also divide grams by 28.3495 for the same result. Both formulas use the avoirdupois ounce, the standard for food, cooking, and everyday use.
What is the difference between an avoirdupois ounce and a troy ounce?
An avoirdupois ounce equals 28.3495 grams and covers food, cooking, postal weight, and everyday commerce. A troy ounce equals 31.1035 grams and is used only for precious metals like gold, silver, and platinum. The troy ounce is about 10% heavier. When a recipe or food label says “ounce,” it means avoirdupois. When a commodity market quotes gold by the ounce, it means troy.
How many grams is 1 ounce?
1 avoirdupois ounce equals exactly 28.349523125 grams, defined by the 1959 International Yard and Pound Agreement. For everyday use, 28.35 grams per ounce is accurate enough for cooking and general measurement.
Why do baking recipes use grams instead of ounces?
Grams offer finer precision for small quantities. One ounce spans 28.35 grams, so a difference of 5 grams is less than 0.18 of an ounce and difficult to measure accurately in imperial units. Professional bakers and most European and Australian recipes use grams because the decimal structure makes scaling and measuring more consistent, which directly affects the texture, rise, and outcome of baked goods.
