How Many Grams Are in an Ounce?

How many grams are in 1 ounce?

1 ounce equals exactly 28.3495 grams, almost always rounded to 28 g for kitchen use. This is the avoirdupois ounce used for weight measurement in the US, UK, and most international cooking contexts. The math: a pound is 16 ounces and 453.6 grams; dividing 453.6 by 16 gives 28.35 g per ounce. For practical cooking, treating an ounce as 28 g gives accuracy within 1 percent, which is well within tolerance for any recipe. Note that this is the weight ounce (dry ounce, avoirdupois), not the fluid ounce. A fluid ounce measures volume (29.57 ml for US, 28.41 ml for UK) and converts to grams differently depending on what's being measured. Water at 1 ml per gram makes the two roughly equivalent (1 fl oz of water weighs about 28 g), but other liquids vary.

How does the ounce compare to other weight units?

Within the US/UK weight system: 1 pound equals 16 ounces, 1 ton (US) equals 2000 pounds, and 1 stone (UK) equals 14 pounds. Within the metric system: 1 kilogram equals 1000 grams, so 1 ounce equals about 0.028 kg. Common conversions: 1 oz is 28 g (rounded), 2 oz is 57 g, 4 oz (1/4 pound) is 113 g, 8 oz (1/2 pound) is 227 g, and 16 oz (1 pound) is 454 g. For baking: an 8 oz package of cream cheese is 227 g (and equals 1 cup), an 8 oz block of butter is also 227 g (and equals 1 cup). The convenient 227 g per 8 oz block makes these dairy ingredients easy to scale across measurement systems.

How many grams are in common ounce amounts?

Standard conversions: 1 oz is 28 g, 2 oz is 57 g, 3 oz is 85 g (single serving meat portion), 4 oz is 113 g (quarter-pound), 5 oz is 142 g, 6 oz is 170 g (standard restaurant portion), 8 oz is 227 g (half-pound, one cup of many ingredients), 12 oz is 340 g, and 16 oz is 454 g (one pound). These figures appear constantly in nutrition labels, recipes, and food packaging. A 5 oz can of tuna is 142 g, a 12 oz beer is 340 ml (close to 340 g for water-based liquids), and a 16 oz steak is 454 g. For precision baking applications, using gram measurements eliminates the rounding error that accumulates across multiple ounce-based ingredients in a single recipe.

When does the ounce-to-gram conversion matter most?

International recipes are the most common case. European, Australian, Canadian, and Asian recipes typically list ingredient weights in grams. Converting from ounces to grams speeds up the cooking. Nutrition tracking is another situation: most calorie tracking apps default to grams for accuracy, since gram measurements give more precise nutritional calculations than ounce approximations. Baking precision benefits substantially. Bread recipes use baker's percentages (ingredients as a percentage of flour weight), which requires gram measurements to work properly. Restaurant cooking standardizes on grams for portion control consistency. Digital scales that read in 0.1 g increments are widely available for kitchen use.