Grams to Ounces Calculator
Enter a weight in grams to get the result in ounces, or flip to ounces and convert back. Choose avoirdupois ounces for everyday items and cooking, or troy ounces for precious metals. The conversion updates instantly and the step-by-step panel shows the exact arithmetic.
Formula
Worked example
100 grams to avoirdupois ounces: 100 / 28.349523 = 3.5274 oz. 100 grams to troy ounces: 100 / 31.1034768 = 3.2151 troy oz. Reverse: 3.5274 oz x 28.349523 = 100 g.
How to convert grams to ounces
To convert grams to avoirdupois ounces, divide the number of grams by 28.349523. The avoirdupois ounce is the everyday ounce used in the United States for food labels, kitchen scales, postal weights, and general commerce. The formula is: ounces = grams / 28.349523. For example, 100 grams / 28.349523 = 3.5274 oz. To reverse it and convert ounces back to grams, multiply by 28.349523: 3.5274 oz x 28.349523 = 100 g.
Avoirdupois ounces versus troy ounces
There are two common ounce types, and confusing them causes real errors. The avoirdupois ounce (28.3495 g) is the standard unit for everyday weights: food, body weight, shipping, and general retail. The troy ounce (31.1035 g) is used exclusively for precious metals and gemstones. Gold, silver, platinum, and palladium spot prices are always quoted in troy ounces. A troy ounce is about 9.7% heavier than an avoirdupois ounce. If you are converting for precious metals, always select "Troy oz" in this calculator to get the accurate result. Using the wrong factor can create a meaningful error in cost calculations: at $2,000 per troy oz, a mix-up of 2.75 g per ounce adds up fast.
Grams to ounces in cooking
Kitchen recipes frequently call for grams (especially in metric countries and professional baking) while US recipes often use ounces and cups. A few anchor points make mental conversions easier: 28.35 g is exactly 1 oz, 113 g is 4 oz (one US stick of butter), 227 g is 8 oz (half a pound), and 454 g is approximately 1 pound (16 oz). When a recipe calls for 100 g of butter, that is about 3.5 oz or just under half a US stick. Digital kitchen scales can switch between grams and ounces, but this converter is handy when you only have a measuring cup or an older scale with one unit.
The gram and the ounce: unit definitions
The gram is the base unit of mass in the metric system (SI). It was originally defined in 1795 as the weight of 1 cubic centimetre of water at its freezing point, and today it is exactly one-thousandth of a kilogram. The kilogram itself is defined by fixing the Planck constant. The avoirdupois ounce is part of the customary US and imperial system. There are 16 ounces in a pound, and the pound is defined as exactly 0.45359237 kilograms, which makes 1 oz = 0.45359237 / 16 = 0.028349523125 kg = 28.349523125 g exactly. That is the exact definition - no rounding.
Grams to Ounces Quick Reference
| Grams (g) | Ounces (oz) | Pounds (lb) | Common reference |
|---|---|---|---|
| 1 | 0.0353 | 0.0022 | 1 paperclip ~1 g |
| 5 | 0.1764 | 0.0110 | 1 tsp of water |
| 10 | 0.3527 | 0.0220 | 2 teaspoons of water |
| 28.35 | 1.0000 | 0.0625 | 1 avoirdupois ounce |
| 31.1 | 1.0971 | 0.0686 | 1 troy ounce (gold) |
| 50 | 1.7637 | 0.1102 | Standard portion in a recipe |
| 100 | 3.5274 | 0.2205 | Small chocolate bar |
| 113 | 3.9860 | 0.2491 | One stick of US butter |
| 200 | 7.0548 | 0.4409 | A cup of granulated sugar ~200 g |
| 250 | 8.8185 | 0.5512 | Standard metric measuring cup fill |
| 454 | 16.0093 | 1.0006 | ~1 pound (lb) |
| 500 | 17.6370 | 1.1023 | Half a kilogram |
| 1000 | 35.2740 | 2.2046 | 1 kilogram |
Avoirdupois ounces (used for food, everyday goods). 1 oz = 28.349523 g. Troy oz (for precious metals) = 31.1035 g each.
Frequently asked questions
How many grams are in an ounce?
There are exactly 28.349523125 grams in one avoirdupois ounce. This is the ounce used for food, shipping, and everyday goods. For precious metals, 1 troy ounce = 31.1034768 grams. For most practical purposes, 28.35 g per ounce is a sufficient approximation.
How do I convert grams to ounces without a calculator?
Multiply grams by 0.03527 for a close result. For example, 200 g x 0.03527 = 7.054 oz. Alternatively, divide by 28.35 (instead of the full 28.349523). For rough mental arithmetic, dividing by 28 gives a slight overestimate but is quick: 100 / 28 = 3.57 oz (vs the exact 3.527 oz).
What is the difference between a troy ounce and a regular ounce?
A regular (avoirdupois) ounce is 28.3495 g. A troy ounce is 31.1035 g, about 9.7% heavier. Troy ounces are used only for precious metals (gold, silver, platinum, palladium) and gemstones. When you see a gold price quoted per ounce, it always means a troy ounce. Food, body weight, and postal scales all use avoirdupois ounces.
How many ounces is 100 grams?
100 grams equals 3.5274 avoirdupois ounces (100 / 28.349523 = 3.5274). In troy ounces, 100 g = 3.2151 troy oz (100 / 31.1035 = 3.2151). The avoirdupois result is more commonly needed for cooking and everyday use.
How many ounces is 200 grams?
200 grams = 7.0548 avoirdupois ounces. In troy ounces, 200 g = 6.4301 troy oz. In pounds, 200 g = 0.4409 lb.
Can I use this calculator to convert ounces back to grams?
Yes. Change the Direction selector to "Ounces to Grams" and enter your ounce value. The formula reverses to: grams = ounces x 28.349523 (avoirdupois) or grams = ounces x 31.1034768 (troy). You can also choose your preferred decimal precision.
Why do my kitchen scale and this calculator give slightly different results?
Kitchen scales typically round to the nearest gram or 0.1 g. This calculator uses the exact defined conversion factor (28.349523125 g per oz), so a result showing 3.5274 oz for 100 g is correct. Any difference is due to rounding on the scale, not an error in the conversion.