Ounces to Grams

1 Ounce (oz) = 28.3495 Gram (g)

Amount

From

Result

28.3495 g

1 oz = 28.3495 g

How Many Grams in an Ounce?

One ounce equals approximately 28.35 grams. To convert ounces to grams, multiply the ounce value by 28.3495. This is one of the most essential conversions for anyone who cooks with recipes from different countries or shops at grocery stores where packaging uses metric weights. If you have ever picked up a steak at the butcher counter labeled in grams and wondered how that compares to the 6 oz portion your recipe calls for, this conversion answers that question. It is equally important for baking, where precision matters and European recipes almost always list ingredients by weight in grams rather than by volume.

How to Convert Ounce to Gram

Start with your weight in ounces.
Multiply the ounce value by 28.3495 to get the weight in grams.
The result is your measurement in grams.
For a quick mental estimate, multiply ounces by 28 or simply by 30 for a rough approximation. For example, 4 oz x 30 = 120 g (actual: 113.4 g).
When a recipe calls for a range (e.g., 4-6 oz of chicken), convert both ends: 4 oz = 113 g and 6 oz = 170 g.

Real-World Examples

A recipe calls for 8 oz of cream cheese. The store sells it in gram packages.

8 x 28.3495 = 226.8 g. A standard metric block of cream cheese is 250 g, so you would use most of the package.

You want to portion 6 oz servings of salmon for meal prep.

6 x 28.3495 = 170.1 g. Set your kitchen scale to grams and weigh out approximately 170 g per portion.

A protein bar label says 2.4 oz. How many grams of protein bar is that?

2.4 x 28.3495 = 68 g. This is a typical single-serve protein bar weight.

Your recipe calls for 12 oz of chocolate chips. The bag is labeled in grams.

12 x 28.3495 = 340.2 g. A standard bag is often 350 g, so you need almost the entire bag.

A serving of deli meat is listed as 2 oz on the nutrition label.

2 x 28.3495 = 56.7 g. This is roughly 2-3 thin slices depending on the cut.

Quick Reference

Ounce (oz)	Gram (g)
1	28.3495
2	56.699
5	141.748
10	283.495
25	708.738
50	1417.48
100	2834.95
500	14174.8
1,000	28349.5

History of Ounce and Gram

The ounce descends from the Roman "uncia," which was one-twelfth of a Roman pound. Over centuries, the ounce took on different values in different regions. The avoirdupois ounce used in cooking today was standardized in the international yard and pound agreement of 1959 at exactly 28.349523125 grams. The gram, meanwhile, was originally defined during the French Revolution as the weight of one cubic centimeter of water at its densest temperature. Today, both units are defined in terms of the kilogram, which since 2019 is anchored to the Planck constant rather than a physical artifact.

Common Mistakes to Avoid

Confusing fluid ounces (a volume measurement) with ounces (a weight measurement). 8 fluid ounces of honey weighs far more than 8 oz because honey is denser than water. Always check whether a recipe means fl oz or oz.
Using 30 as the conversion factor instead of 28.35. While 30 is useful for quick mental math, it introduces a 5.8% error that compounds with larger quantities. For a 16 oz measurement, using 30 gives 480 g instead of the correct 453.6 g.
Forgetting that nutrition labels in the US list serving sizes in both ounces and grams, but the gram value is often rounded. Always use the conversion factor rather than relying on rounded label values.

Frequently Asked Questions

Is the ounce used in cooking the same as a troy ounce?

No. Cooking uses the avoirdupois ounce (28.35 g). The troy ounce (31.10 g) is used for precious metals like gold and silver. Using the wrong ounce type would throw off your recipe by about 10%.

Why do recipes use ounces instead of grams?

Recipes from the United States, United Kingdom, and other countries with imperial traditions use ounces because that is the measurement system home cooks there are familiar with. Professional bakers worldwide tend to prefer grams because they are more precise and easier to scale.

How do I convert ounces to grams without a calculator?

A useful shortcut: 1 oz is roughly 28 g. For quick estimates, multiply ounces by 28. For even faster math, remember that 4 oz is about 113 g and 8 oz is about 227 g, then work from those benchmarks.

Should I measure ingredients by weight or volume for baking?

Weight (grams or ounces) is more accurate for baking because volume measurements like cups vary depending on how tightly you pack the ingredient. A cup of flour can weigh anywhere from 120 g to 160 g depending on technique, but 150 g on a scale is always 150 g.

Quick Tip

When grocery shopping, remember these common serving size benchmarks: a typical chicken breast is 6-8 oz (170-227 g), a standard burger patty is 4 oz (113 g), and a recommended serving of meat is 3 oz (85 g), which is roughly the size of a deck of cards.