A US cup is 236.6 mL (8 US fluid ounces). A metric cup, used in Australia, New Zealand and Canada, is 250 mL, about 6% bigger. The UK has no standard cup in modern use: British recipes are written in grams and milliliters, and when one does say “cup” it usually means a US cup or an everyday cup used loosely. Japan uses a 200 mL cup, and rice cookers come with a cup of about 180 mL.
How big is a cup in each country? #
| Cup | Milliliters | US fluid ounces | US tablespoons |
|---|---|---|---|
| US customary cup | 236.6 | 8.00 | 16.0 |
| US nutrition-label cup | 240 | 8.12 | 16.2 |
| Metric cup (Australia, NZ, Canada) | 250 | 8.45 | 16.9 |
| Japanese cup | 200 | 6.76 | 13.5 |
| Rice cooker cup (gō) | about 180 | 6.09 | 12.2 |
The US customary cup comes from the US gallon: 1 gallon (exactly 3.785411784 L) holds 16 cups, so a cup is 236.5882365 mL. The nutrition-label cup is a rounder 240 mL, set by FDA rules that say “a cup means 240 mL” for labeling purposes (21 CFR 101.9). Your measuring cups are the 236.6 mL kind.
Canada used an 8 imperial fluid ounce cup (227 mL) in older recipes but now uses the 250 mL metric cup.
What about the UK? #
Modern British recipes use grams for dry ingredients and milliliters for liquids, and older ones used imperial pints and fluid ounces. There’s no official British cup measure in current use. Traditional recipes that said “a cup” often meant an ordinary teacup or breakfast cup, which were never standardized.
So if a British recipe gives cups, look for gram or milliliter amounts alongside them and use those. If there are none, the writer most likely meant US cups, especially on websites aimed at an international audience.
How much difference does the cup make? #
The metric cup is 5.7% bigger than the US cup. For liquids you can often ignore that. For dry baking ingredients it adds up:
| Ingredient | 1 US cup | 1 metric cup (250 mL) |
|---|---|---|
| All-purpose flour | 120 g | 127 g |
| Granulated sugar | 198 g | 209 g |
| Butter | 227 g | 240 g |
US figures are from King Arthur Baking’s weight chart, scaled up for the metric cup. A recipe with 3 cups of flour would use 360 g in US cups and 380 g in metric cups. That 20 g won’t ruin most cookies, but it can change a bread dough or a delicate cake.
Spoons differ too. Australia’s tablespoon is 20 mL, where the US tablespoon is 14.8 mL and most other countries use 15 mL. The details are in how many tablespoons are in a cup.
How do you tell which cup a recipe means? #
- Check for grams or milliliters. If the recipe gives them, use them and ignore the cups.
- Check where it’s from. Australian and New Zealand recipes use 250 mL cups and often 20 mL tablespoons (Australia). US recipes use 236.6 mL cups. Japanese recipes use 200 mL.
- Look at the measuring set it mentions. “250 mL cup” printed in the ingredient list settles it.
- Rice cooker recipes mean the plastic cup that came with the cooker, about 180 mL. Using a US cup instead gives you about 30% more rice than the recipe expects.
How do you convert between cups? #
Go through milliliters:
- Metric cups to US cups: multiply by 250 ÷ 236.6 = 1.057.
- US cups to metric cups: multiply by 0.946.
- Japanese cups to US cups: multiply by 200 ÷ 236.6 = 0.845.
Worked examples #
An Australian recipe calls for 1 cup of milk. That’s 250 mL, which is 1 US cup plus about 1 tablespoon (13.4 mL).
An Australian recipe calls for 2 cups of flour. In US cups that’s 2.11, or 2 cups plus about 1 3/4 tablespoons. Better, weigh it: about 254 g.
A Japanese recipe calls for 1 cup of water. That’s 200 mL, a little over 3/4 US cup (177 mL) plus 1 1/2 tablespoons.
A US recipe calls for 1 1/2 cups of stock and your jug is metric. 1.5 × 236.6 = 355 mL.
Converting cups on your phone #
Convert Units Calculator converts US cups to milliliters, liters, fluid ounces and spoons in its Volume category, and version 1.0.5 lists UK pints and fluid ounces separately from US ones. Its Cooking category, also in 1.0.5, turns cups of 26 ingredients into grams, but its cup is the US 236.6 mL cup. For a metric or Japanese cup, enter the amount in milliliters (250 or 200 per cup) and convert from there.
For gram weights of other ingredients, see the cups to grams conversion chart, and for flour specifically, grams in a cup of flour. The US/UK split runs through larger measures too, covered in US gallon vs imperial gallon.
Frequently asked questions #
Is a UK cup the same as a US cup? #
There isn’t an official UK cup in modern use. British recipes normally use grams and milliliters. If a British recipe says “cup” without metric amounts, it’s most often borrowing the US cup.
Is a cup 250 mL? #
A metric cup is 250 mL, used in Australia, New Zealand and Canada. A US cup is 236.6 mL, and a US nutrition label treats a cup as 240 mL.
How many mL are in an Australian cup? #
250 mL. Australian tablespoons are also larger than elsewhere, at 20 mL.
What size is a rice cooker cup? #
About 180 mL, based on the traditional Japanese gō. It’s smaller than both the US cup (236.6 mL) and the Japanese kitchen cup (200 mL), so always use the cup that came with the cooker.
Does the cup size matter for baking? #
It can. A metric cup holds about 6% more than a US cup, which adds up across several cups of flour or sugar. When a recipe gives weights, use them instead of either cup.