How many ounces is 100 grams?

100 grams equals 3.5274 ounces (avoirdupois). The exact conversion factor is 1 oz = 28.349523125 g, so 100 g divided by 28.349523125 gives 3.52739619... oz, which rounds to 3.527 oz to three decimal places.

What is the difference between avoirdupois ounces and troy ounces?

Avoirdupois ounces (oz av) are the standard ounce used for everyday goods, food, and postage. One avoirdupois ounce equals 28.349523125 grams. Troy ounces (oz t) are used for precious metals such as gold and silver. One troy ounce equals 31.1034768 grams, making it about 10% heavier than an avoirdupois ounce. This calculator uses avoirdupois ounces unless you select the troy option.

How do I convert ounces back to grams?

To convert ounces to grams, multiply the number of ounces by 28.349523125. For example, 5 oz x 28.349523125 = 141.748 g. This calculator includes a reverse field so you can enter ounces and read the grams result directly.

Grams to Ounces Calculator

This calculator converts grams to ounces, and ounces back to grams, using the exact international conversion factor of 1 oz = 28.349523125 g. Grams are the standard metric unit for weighing small amounts, from food and spices to jewellery and postage, while ounces are still widely used in recipes, gym equipment, and precious metal pricing, so having an accurate way to move between the two saves you from rounding errors and guesswork. Enter a weight in grams, or type a figure straight into the ounces field to convert the other way, and choose whether you want avoirdupois ounces (the everyday standard used for food and general goods) or troy ounces (used for gold, silver, and other precious metals, and about 9.7% heavier). The calculator instantly returns the result in ounces, the equivalent in grams, a pounds-and-ounces breakdown for reference, and the underlying conversion factor, along with a quick reference table covering common weights from one ounce up to a kilogram. Nine preset buttons let you jump straight to typical NZ pack sizes like 125 g butter blocks, 250 g, 500 g, and 1 kg without typing. Because avoirdupois and troy ounces differ, always check which type you need, especially when weighing precious metals.

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Verified 2026 International avoirdupois standard: exactly 1 lb = 453.59237 g, therefore 1 oz = 28.349523125 g.

1. Convert Grams to Ounces

Grams (g)

Ounce type

Result in ounces

You can also type ounces here to convert back to grams.

2. Quick Presets

Click a common quantity to fill it in.

Conversion Result

Ounces
3.5274
avoirdupois oz

Grams

100

Pounds and Ounces

0 lb 3.5274 oz

for reference

Conversion Factor

0.03527

oz per gram

Quick Reference Table

Grams (g)	Avoirdupois oz	Troy oz	Pounds + oz

Result: 100 g = 3.5274 avoirdupois oz (or 0.2205 lb at 16 oz/lb)

How to Convert Grams to Ounces

The avoirdupois ounce is the standard ounce used in everyday life for food, postage, and general goods. The international standard defines 1 pound (lb) as exactly 453.59237 grams. Since there are 16 ounces in a pound, 1 oz = 453.59237 / 16 = 28.349523125 g exactly.

To convert grams to ounces, divide by 28.349523125:

Ounces = Grams / 28.349523125

To go the other way (ounces to grams), multiply by 28.349523125:

Grams = Ounces x 28.349523125

Worked Example

Convert 100 grams to ounces:

Divide by the conversion factor: 100 / 28.349523125
Result: 3.5274 oz (avoirdupois, rounded to 4 decimal places)

This matches the default output shown in the calculator above.

Avoirdupois vs Troy Ounces

There are two ounce systems in common use:

Ounce type	Grams	Common uses
Avoirdupois oz (oz av)	28.349523125 g	Food, postage, general goods, body weight in some countries
Troy oz (oz t)	31.1034768 g	Gold, silver, platinum, gemstones

The troy ounce is about 9.7% heavier than the avoirdupois ounce. If you are converting precious metal weights, use the troy option in this calculator.

Common Conversions

Grams	Avoirdupois oz	Context
28.35 g	1.000 oz	One ounce of food or spice
100 g	3.527 oz	Typical serving or small pack
125 g	4.409 oz	Common NZ butter block size
250 g	8.818 oz	Half-pound equivalent
454 g	16.014 oz	1 lb (approximately)
500 g	17.637 oz	Standard half-kilogram pack
1,000 g	35.274 oz	1 kilogram

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Sources and method: International Bureau of Weights and Measures (BIPM): the avoirdupois pound is defined as exactly 453.59237 grams (NIST Handbook 44). Troy ounce: 1 troy pound = 12 troy oz = 373.2417216 g, giving 1 troy oz = 31.1034768 g (London Bullion Market Association, ISO 4217 XAU convention).

This calculator uses the international avoirdupois standard by default. For precious metal weights, select the troy ounce option. Results are rounded to four decimal places for display; the underlying computation uses full precision.