Cooking Measurement Converter

Why "1 cup = 240 g" is wrong

A cup is a measure of volume. A gram is a measure of mass. Converting between them requires knowing the density of what you are measuring, and ingredients differ enormously.

That is a threefold spread between oats and honey for the identical volume. Any converter offering a single cups-to-grams number is giving you the right answer for at most one ingredient. The dry-goods figures here follow the King Arthur Baking weight chart, which is the reference most English-language recipes are now standardised against.

Flour is where recipes go wrong

Flour is the most compressible common ingredient and the one where volume measurement fails worst. A cup scooped directly from the bag can hold 140 g or more, because the scooping action packs it. The same cup filled by spooning flour in loosely and levelling off holds about 120 g.

That is a 17% difference from technique alone, on the ingredient that most determines whether a bake is tender or tough. It is the single biggest reason the same recipe turns out differently for different people, and it is why serious baking recipes give weights.

If a recipe gives only cups and you want to weigh, 120 g per cup of all-purpose flour is the standard assumption — but if the results come out dry, the recipe author was probably scooping, and 130 to 140 g is closer to what they meant.

The water discrepancy

You will find charts listing a cup of water as 227 g and others as 237 g. Both are defensible and they mean different things. A US customary cup is 236.588 ml, and water is very close to 1 g per ml, so a cup of water genuinely weighs about 237 g. The 227 g figure comes from the convention that 8 fluid ounces equals 8 avoirdupois ounces — neat, memorable, and about 4% off. This converter uses real density for liquids.

Cups are not the same everywhere

The Australian tablespoon is also the odd one out at 20 ml, against 15 ml almost everywhere else — four teaspoons rather than three. In a recipe using several tablespoons of a strong ingredient, that difference is noticeable.

Oven temperatures

Fan ovens circulate air, so they cook faster at the same setting. The convention is to drop about 20 °C from the conventional figure, or reduce the time by roughly a fifth. Most domestic ovens are also several degrees off their dial — an oven thermometer costs very little and settles a lot of arguments about why things bake unevenly.

Just weigh it

A digital scale removes the entire problem. It is faster once you are used to it, since you can tare between additions and use one bowl instead of a stack of measuring cups. It is more consistent, because 120 g is 120 g regardless of how you scooped. And it makes scaling trivial — halving 187 g is arithmetic, while halving three-quarters of a cup is fiddly.

How many grams is one cup?

It depends entirely on the ingredient, which is the whole point. A cup of rolled oats is 113 g, all-purpose flour 120 g, granulated sugar 198 g, butter 227 g, water 237 g and honey 336 g — a threefold spread for the identical volume. Any converter that gives a single cups-to-grams figure is right for at most one ingredient, which is why this one asks you to pick.

Why does my baking come out differently from the recipe?

Usually flour measurement. A cup scooped straight from the bag packs down and can hold 140 g or more; the same cup filled by spooning flour in loosely and levelling holds about 120 g. That 17% swing comes from technique alone, on the ingredient that most affects texture. It is the main reason the same recipe behaves differently for different people, and why serious baking recipes give weights.

Is a cup of water 227 g or 237 g?

About 237 g. A US customary cup is 236.588 ml and water is essentially 1 g per ml. The 227 g figure comes from treating 8 fluid ounces as 8 ounces by weight, which is a tidy convention but about 4% off. Some charts use it for all liquids, which compounds the error. This converter uses real density for liquids and the standard baking chart figures for dry goods.

Are cups the same size in every country?

No. A US customary cup is 236.6 ml, the US legal cup used on nutrition labels is 240 ml, the metric cup used in Australia, New Zealand, Canada and the UK is 250 ml, and a Japanese cup is 200 ml. The Australian tablespoon is also 20 ml against 15 ml elsewhere — four teaspoons rather than three. This tool uses the US customary cup, which is what most online recipes assume.

Should I use a scale instead of cups?

For baking, yes. It is more consistent, since a weight does not depend on how you scooped; it is usually faster, because you can tare between additions and use one bowl; and it makes scaling a recipe up or down trivial. Cups remain fine for liquids and for cooking where precision matters less. Most experienced bakers switched to weight and did not go back.