Cups to grams: why weighing baking ingredients works better

Weighing ingredients in grams gives you the same amount every time, while a cup measures volume, and a cup of the same ingredient can weigh quite different amounts depending on how it was filled. To convert a recipe, multiply the number of cups by the grams per cup for that ingredient. Use a converter for the common ingredients, and weigh them whenever you can.

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Why a cup is not a fixed weight

A measuring cup holds a fixed volume, but a given volume of flour can contain different amounts of flour. Scooping straight from the bag packs the flour in, so the cup can end up heavier than a cup spooned gently in and levelled. Brown sugar, which is packed on purpose, has the same problem. Liquids are more consistent, but a cup of honey is much heavier than a cup of water.

The King Arthur Baking ingredient weight chart lists 120 grams for a cup of all-purpose flour, and it does not say how the cup was filled. That gap is the reason a recipe can fail when the flour quantity varies between bakers.

US, metric and Australian measures

Three different cup sizes are in common use:

• The US customary cup is 236.59 ml (8 US fluid ounces).
• The metric cup is 250 ml, and Australian recipes use it. That is about 6 percent more than the US cup.
• The US nutrition-label cup is 240 ml, as set for food labelling.

The tablespoon differs even more. Australia's tablespoon is 20 ml, which is four teaspoons. The US customary tablespoon is about 14.8 ml, and many US recipes and food labels use 15 ml. A recipe that calls for "1 tablespoon" from an Australian source is about a third bigger than the same words from a US source. When in doubt, use grams.

Grams per cup: a reference table

The King Arthur chart gives these amounts. Each one is the amount printed on the chart, so the measure in the second column is the one the chart uses.

Ingredient	Measure	Grams
All-purpose flour	1 cup	120
Granulated sugar	1 cup	198
Brown sugar, packed	1 cup	213
Powdered sugar, unsifted	1 cup	113
Rolled oats	1 cup	113
Almond flour	1 cup	96
Water or milk	1 cup	227
Butter	½ cup (8 tablespoons)	113
Cocoa, unsweetened	½ cup	42
Honey	1 tablespoon	21
Table salt	1 tablespoon	18

The chart also shows that salt needs care. Kosher salts differ by brand: the chart lists 8 g per tablespoon for one brand and 16 g per tablespoon for another. Weighing salt avoids that problem completely.

How to convert a recipe

1. Find the ingredient in the table or in the cooking converter.
2. Multiply the cups by the grams per cup.
3. For parts of a cup, convert the fraction first with a fraction calculator, or multiply by the decimal.

Worked examples:

• 1.5 cups of flour: 1.5 × 120 = 180 g.
• 2¼ cups of flour: 2.25 × 120 = 270 g.
• ½ cup of granulated sugar: 0.5 × 198 = 99 g.

To convert the other way, divide grams by the grams per cup. The unit converter handles the same steps for other units.

Oven temperatures and fan ovens

Fan, or convection, ovens circulate hot air, which cooks faster and more evenly. Recipe guides commonly advise setting a fan oven about 20 °C below the temperature in a recipe written for a conventional oven, and checking the bake earlier than the recipe says. Gas mark 4 is usually 180 °C conventional and 160 °C fan. Your oven's manual is the best guide, because models vary.

Converting Fahrenheit and Celsius uses one formula: °F = °C × 9 ÷ 5 + 32. So 180 °C is 180 × 1.8 + 32 = 356 °F, and 160 °C is 320 °F. For a fuller comparison, read Celsius and Fahrenheit in your head.

Mistakes to avoid

• Weighing with a scale that is not tared. Reset the scale to zero after you add the bowl.
• Confusing a fluid ounce with an ounce of weight. A fluid ounce measures volume, and an ounce of weight measures mass. A gram is a unit of mass in every country.
• Mixing measures in one recipe. Convert the whole recipe to grams before you start.

Quick answers

Is a cup always 240 grams? No. The cup varies by country, and by ingredient. 240 ml is the US labelling cup, not a universal baking standard.

Do I need a scale to bake well? Not for everything, but a scale is the easiest way to get consistent results with flour, sugar and salt.

Are grams the same everywhere? Yes. A gram is the same in every country, which is why a weight-based recipe travels well.

What about the metric and US tablespoon? Many US recipes treat a tablespoon as 15 ml, and Australian recipes use 20 ml. Check which country the recipe comes from.

For the wider picture on unit conversions, see metric and imperial conversions.