US, UK & Metric Cups: Why They Are Not the Same

If you have ever followed a recipe carefully and still had it fail, the culprit may be the word "cup." It does not mean one fixed amount around the world.

Three different cups

• US customary cup: 236.6 ml — the most common in online recipes.
• Metric cup: 250 ml — used in Australia, New Zealand, and parts of Canada.
• UK / Imperial cup: historically about 284 ml, though modern UK recipes usually use grams or millilitres instead.

The gap between a US cup and a metric cup is about 6%. On one cup of flour that is a small difference; across a whole recipe of flour, sugar, and liquid it adds up enough to matter.

How to tell which cup a recipe means

• US recipes use Fahrenheit for oven temperatures and sticks of butter.
• Australian and NZ recipes use Celsius and the 250 ml metric cup.
• UK recipes usually skip cups entirely and give grams and millilitres.

The reliable fix: use weight

Grams mean the same thing everywhere. The simplest way to make any recipe portable is to convert its cups to grams once. Our per-ingredient converters use the US cup as the starting point, so if you have a US recipe you can convert it straight to grams and never think about cup sizes again.

Spoons are nearly universal

One small comfort: tablespoons and teaspoons are almost the same worldwide (the Australian tablespoon is the one exception, at 20 ml instead of 15 ml). For everything else, weight is your friend — see our guide to tablespoons and teaspoons.