Ounces to Grams Converter

Why You Are Here

You are most likely on this page because something you are working with uses ounces while everything else around you uses grams. That happens in four very specific situations. You are following an American recipe on a kitchen scale that only shows grams. You are reading a US food nutrition label that lists serving sizes in ounces but your fitness app tracks in grams. You are weighing a parcel and the recipient's country uses metric postal standards. Or you are buying or selling silver or gold and need to understand the gram equivalent of a troy ounce price.

Important: This converter handles cooking, food, postal, and everyday weight using the avoirdupois ounce of 28.3495 grams. If you are working with precious metals, read the Avoirdupois vs Troy section below before converting since gold and silver use troy ounces which are heavier at 31.1035 grams.

The Conversion Factor and Formula

1 avoirdupois ounce = 28.349523125 grams exactly. This is the legal definition used for all food, postal, and everyday weight measurements in the United States and United Kingdom. It has been standardized since 1959 under the International Yard and Pound Agreement.

Formula: Grams = Ounces x 28.3495

Example: Convert 4 oz to grams
4 x 28.3495 = 113.398 grams

// This is the weight of one standard US butter stick
// listed as 4 oz on packaging, 113g on metric scales

Common oz to g Conversion Examples

Quick reference for the most frequently needed ounce to gram conversions in cooking and everyday use:

Ounces (oz)	Grams (g)	Common Context
0.25 oz	7.09 g	Quarter ounce, typical spice measurement
0.5 oz	14.17 g	Half ounce, small herb or extract portion
1 oz	28.35 g	Base conversion, standard serving size reference
1.5 oz	42.52 g	One and a half ounces
2 oz	56.70 g	Two ounces, small chocolate bar
2.5 oz	70.87 g	Two and a half ounces
3 oz	85.05 g	Three ounces, standard chicken serving in nutrition plans
3.5 oz	99.22 g	Three and a half ounces, common meat portion
4 oz	113.40 g	Four ounces, one stick of butter
5 oz	141.75 g	Five ounces, standard protein serving
6 oz	170.10 g	Six ounces, average chicken breast
8 oz	226.80 g	Eight ounces, half pound
10 oz	283.50 g	Ten ounces, standard ground beef package
12 oz	340.19 g	Twelve ounces, standard pasta portion
16 oz	453.59 g	Sixteen ounces, one full pound

Avoirdupois vs Troy Ounces

If you are converting ounces to grams for cooking, food labels, or postal weight, use this converter directly. The avoirdupois ounce of 28.3495 grams is the correct standard.

If you are working with gold, silver, platinum, or other precious metals, you need the troy ounce which equals 31.1034768 grams — almost 10 percent heavier than the everyday ounce. At gold prices near $2,000 per troy ounce, the difference between using the wrong ounce type is approximately $180 per ounce in value. Never use a standard avoirdupois converter for precious metals calculations.

Ounce Type	Grams	Used For
Avoirdupois oz	28.3495 g	Food, postal, everyday weight
Troy oz	31.1035 g	Gold, silver, platinum, gemstones

Nutrition Label Use — Reading oz on US Food Packaging

US food nutrition labels list serving sizes in both grams and ounces. When following an international recipe or tracking macros on a metric-based fitness app, you need the gram equivalent of the ounce serving size listed.

Label oz Serving	Grams (g)	Common Food Example
1 oz serving	28 g	Standard snack chip serving
1.5 oz serving	43 g	Cereal or granola portion
2 oz serving	57 g	Pasta dry weight serving
3.5 oz serving	99 g	Meat or fish fillet serving
4 oz serving	113 g	Burger patty or protein portion
6 oz serving	170 g	Chicken breast, standard fitness meal prep

Note: Nutrition labels round to the nearest gram. This converter gives you the precise mathematical result. The small rounding difference is normal and does not affect macro tracking accuracy.

Common Mistakes to Avoid

Using Troy Ounces for Everyday Conversions

If you googled ounces to grams because you saw a gold price quoted in ounces, be aware that gold uses troy ounces of 31.1035 grams not the standard 28.3495 grams. Using this converter for precious metals will give you a result that is 2.75 grams short per ounce, which at gold prices represents a significant financial error.

Confusing Fluid Ounces with Weight Ounces

A US fluid ounce measures volume not weight. One fluid ounce of water weighs approximately 29.57 grams, not 28.35 grams, because water has a density slightly greater than the exact conversion factor. This converter works for weight ounces only. If you need to convert fluid ounces to grams for water or other liquids, you need to account for the specific density of the liquid.

Rounding 28.3495 to 28 or 30

For casual cooking purposes rounding is acceptable. For pharmaceutical compounding, scientific measurement, or postal weight calculations where the fee changes at specific gram thresholds, always use the full factor of 28.3495 to avoid being over or under by enough grams to matter.

Quick Reference Values

Ounces (oz)	Grams (g)
0.25 oz	7.09 g
0.5 oz	14.17 g
1 oz	28.35 g
2 oz	56.70 g
3 oz	85.05 g
4 oz	113.40 g
5 oz	141.75 g
6 oz	170.10 g
8 oz	226.80 g
10 oz	283.50 g
12 oz	340.19 g
16 oz	453.59 g

Frequently Asked Questions

How many grams are in an ounce?

There are exactly 28.349523125 grams in one avoirdupois ounce. This is the standard used for all food, postal, and everyday weight measurements in the United States and United Kingdom. Use this Ounces to Grams Converter to calculate any ounce value instantly.

What is the formula to convert ounces to grams?

Multiply the number of ounces by 28.3495. For example, 5 ounces multiplied by 28.3495 equals 141.748 grams. This single multiplication covers every oz to g conversion you will need for cooking and everyday use.

What is 1 oz in grams?

1 ounce equals 28.3495 grams. This is the most searched ounce to gram conversion and the base value for all calculations on this page.

What is 4 oz in grams?

4 ounces equals 113.398 grams. This is one of the most practically important conversions because 4 oz is the weight of a standard US butter stick, a common recipe ingredient that international bakers frequently need to convert.

What is 6 oz in grams?

6 ounces equals 170.097 grams. This is a common protein serving size in nutrition and meal prep contexts. A standard chicken breast typically weighs between 5 and 7 ounces raw, making 6 oz the most commonly referenced weight for protein tracking.

How many grams is a troy ounce?

A troy ounce equals exactly 31.1034768 grams. This is different from the everyday avoirdupois ounce of 28.3495 grams. Troy ounces are used exclusively for precious metals including gold, silver, and platinum. This Ounces to Grams Converter uses avoirdupois ounces and is not suitable for precious metals calculations.

Why do US recipes list ingredients in ounces while international recipes use grams?

American cooking tradition developed from the imperial measurement system where weight is expressed in ounces and pounds. Most international recipes use the metric system where weight is expressed in grams and kilograms. Neither system is more accurate — the difference is purely historical and regional. Using this Ounces to Grams Converter bridges the gap instantly without needing to own two different recipe books.

Can I use this converter for postal and shipping weight?

Yes. This Ounces to Grams Converter uses the standard avoirdupois conversion factor of 28.3495 grams per ounce which is the same standard used by USPS, Royal Mail, and international postal services for calculating weight-based postage rates.

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