How many millilitres is one cup?

It depends on the country. A US legal cup is 240 ml, a US customary cup is about 237 ml, a metric cup (Australia, NZ, Canada) is 250 ml, an old UK imperial cup is 284 ml, and a Japanese cup is 200 ml.

Is a US cup the same as a metric cup?

No. A US cup is 240 ml while a metric cup is 250 ml, a difference of about 4%. For most recipes this is small, but it adds up when a recipe uses several cups.

Cup Sizes Around the World

A "cup" isn't one fixed amount — it ranges from 200 ml in Japan to 284 ml in old UK recipes. Pick a cup type to see it in millilitres.

Cup size comparison

Cup type	1 cup	Where it's used
US legal cup	240 ml	US nutrition labels
US customary cup	237 ml	Traditional US recipes
Metric cup	250 ml	Australia, NZ, Canada, modern UK
Imperial cup	284 ml	Historic UK
Japanese cup	200 ml	Japan

Which cup should you use?

Follow the origin of your recipe. A recipe from a US site almost always means the US cup (240 ml on labels, ~237 ml traditionally). A recipe from Australia, New Zealand or Canada uses the metric cup of 250 ml. Very old British recipes may use the imperial cup of 284 ml, though modern UK recipes have largely switched to grams and millilitres.

The gap between a US cup (240 ml) and a metric cup (250 ml) is only about 4%, so a single cup rarely matters. But across a recipe that uses several cups of liquid, the difference can affect the result — which is why weighing ingredients in grams is the most reliable method. For ingredient-by-ingredient gram weights, use our cups to grams converters.