Ounces to Grams Calculator

Converting ounces to grams is a straightforward mathematical calculation. Unlike grams-to-tablespoons or grams-to-cups conversions (which depend on ingredient density), ounces and grams both measure mass. The conversion factor is a fixed constant — it never changes regardless of what you're weighing.

To convert ounces to grams, multiply the weight in ounces by the conversion factor:

The precise conversion factor is 28.349523125 grams per ounce, defined by the International Yard and Pound Agreement of 1959. In practice, rounding to 28.3495 g/oz introduces less than 0.0001% error — negligible for all cooking and most laboratory applications.^[2]

How Many Grams Is 1 Ounce?

1 ounce = 28.35 grams. This is the foundational conversion constant. One ounce is roughly the weight of a standard slice of bread, a single AA battery, or about 6 US quarters stacked together.

How Many Grams Is 2 Ounces?

2 ounces = 56.70 grams. This is approximately the weight of a small chocolate bar, a single large egg without the shell, or 2 tablespoons of butter.

How Many Grams Is 4 Ounces?

4 ounces = 113.40 grams = ¼ pound. In US baking, 4 oz is exactly 1 stick of butter (½ cup). This is one of the most commonly used conversions in American kitchens. When a recipe calls for "4 ounces of chocolate," weigh out 113g on your kitchen scale.

How Many Grams Is 6 Ounces?

6 ounces = 170.10 grams. This is approximately the weight of a standard single-serve yogurt container, a medium chicken breast, or ¾ of a standard US butter stick pair.

How Many Grams Is 8 Ounces?

8 ounces = 226.80 grams = ½ pound. In US baking, 8 oz equals 2 sticks of butter (1 cup). This is also the weight of a standard block of cream cheese. Do not confuse 8 dry ounces (weight) with 8 fluid ounces (volume) — they are completely different measurements.

How Many Grams Is 12 Ounces?

12 ounces = 340.19 grams = ¾ pound. This is the weight of a standard bag of chocolate chips (Nestlé Toll House), a can of soda, or 3 sticks of butter. When baking a cake that calls for 12 oz of flour, weigh out 340g.

How Many Grams Is 16 Ounces?

16 ounces = 453.59 grams = exactly 1 pound. This is the most important ounce-to-gram conversion to memorize. One pound equals 16 ounces, which equals 453.59 grams. A standard box of pasta, a pound of ground beef, or 4 sticks of butter all weigh approximately 1 pound.

How Many Grams Is 32 Ounces?

32 ounces = 907.18 grams = 2 pounds. This is approximately the weight of a standard container of yogurt (quart size) or a large bag of shredded cheese. At nearly 1 kilogram, 32 oz is a useful benchmark for larger bulk recipe quantities.

Ounce to Gram Conversion Chart

Use this master reference table for quick ounce-to-gram lookups. The "Kitchen Reference" column provides real-world context for common US food weights sourced from the USDA FoodData Central and King Arthur Baking.^[4][5]

Ounces vs. Troy Ounces — A Critical Distinction

The ounce used in cooking and everyday weighing is the avoirdupois ounce (28.3495g). This is what our calculator converts. However, there is a completely different unit called the troy ounce (31.1035g), which is used exclusively for weighing precious metals like gold, silver, and platinum.^[1]

A troy ounce is approximately 10% heavier than a standard ounce. If you see gold priced at "$2,000 per ounce," that's per troy ounce. Never use troy ounces for cooking — your recipes will be off by 10%.

When to Convert Ounces to Grams

Ounces and grams are both units of mass commonly used in American kitchens and laboratories. The NIST recommends measuring ingredients by weight for improved accuracy.^[1]

• Following metric recipes: Most international recipes specify ingredients in grams. If your kitchen scale reads in ounces, you need to convert. Or switch your scale to grams — most modern digital scales support both units.
• Precise baking measurements: Professional bakers measure flour, sugar, and butter in grams because it eliminates the inconsistency of cup measurements. Converting your familiar ounce amounts to grams is the first step to more consistent results.
• Nutritional tracking: The FDA requires all US nutrition labels to display serving sizes in grams.^[3] If you're tracking macros and your food scale reads in ounces, you'll need to convert to match the label.
• Scaling recipes: When using our recipe scale calculator for large batches, converting everything to grams first prevents rounding errors that compound when multiplying fractional ounce amounts.
• International shipping: Most countries outside the US use the metric system. Package weights must be listed in grams or kilograms for international commerce.

Common Mistakes When Converting Ounces to Grams

• Confusing dry ounces with fluid ounces — A dry ounce (oz) measures weight. A fluid ounce (fl oz) measures volume. 1 fl oz of water weighs approximately 29.57g (not 28.35g). 1 fl oz of honey weighs about 42g. They are completely different units. Use our milliliters to grams converter for volume-based measurements.
• Using troy ounces for cooking — If you're using a jewelry scale or a precious metals calculator, it likely uses troy ounces (31.1g). This creates a 10% error in your recipes.
• Rounding too aggressively — Using "28 grams per ounce" instead of 28.35g introduces a 1.2% error. For a single ounce, that's only 0.35g — negligible. But for a 5-lb bag of flour (80 oz), the error grows to 28g — nearly an extra ounce. Always use at least 28.35g/oz.
• Confusing ounces with tablespoons or cups — Ounces measure weight. Tablespoons and cups measure volume. You cannot convert ounces directly to tablespoons without knowing the ingredient's density.

What Is an Ounce?

An ounce (oz) is a US customary and imperial unit of mass equal to 1/16 of a pound, or 28.349523 grams. The term "ounce" refers to the avoirdupois ounce, which is the standard unit of weight used in the United States for food, commerce, and everyday measurement. The avoirdupois system has been the legal standard in the US since 1959, when the International Yard and Pound Agreement defined 1 pound as exactly 0.45359237 kilograms.^[2]

Ounces can be abbreviated as oz — for example, 1 ounce can be written as 1 oz. The common ounce should not be confused with the troy ounce (oz t), which equals 31.1035g and is used exclusively for precious metals.

What Is a Gram?

A gram (g) is a metric unit of mass equal to 1/1,000 of a kilogram, or 0.035274 ounces. It is equivalent to the mass of one cubic centimeter (one milliliter) of water at 4°C. The gram is an SI unit of mass in the metric system and can be abbreviated as g — for example, 1 gram can be written as 1 g.

The gram is the most commonly used unit for measuring food ingredients worldwide. In the United States, while ounces and pounds dominate everyday usage, grams are required on all FDA nutrition labels and are the preferred unit for precise baking.^[3]

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