Cup Sizes Around the World: US Customary, Legal, Metric, Imperial & Japanese

Cup sizes vary by country: The US Customary Cup is 236.59 mL (8 fl oz); the US Legal Cup is 240 mL; the Metric Cup (used in Australia, NZ, UK, Commonwealth) is 250 mL; the historical UK Imperial Cup is 284.13 mL (10 Imp fl oz); and the Japanese Cup is 200 mL.

Explore our authoritative reference tables, deep-dive technical explanations, practical troubleshooting tips, and FAQs below.

International Cup Volume Standards Comparison Matrix

Verified Reference Data

Cup Standard Name	Volume in Milliliters (mL)	Volume in US Fluid Oz	Primary Countries Using Standard	Flour Weight Equivalent (g)
US Customary Cup	236.59 mL	8.00 US fl oz	United States (Traditional Recipes)	125.0g
US Legal Cup (FDA)	240.00 mL	8.12 US fl oz	United States (Nutrition Labels)	126.8g
Metric Cup	250.00 mL	8.45 US fl oz	Australia, New Zealand, UK, Canada, South Africa	132.0g
UK Imperial Cup (Historical)	284.13 mL	9.61 US fl oz	United Kingdom (Pre-1975 Vintage Recipes)	150.0g
Japanese Cup (Gō / Metric)	200.00 mL	6.76 US fl oz	Japan (Rice Cookers & Modern Baking)	105.0g
Traditional Japanese Gō	180.39 mL	6.10 US fl oz	Japan (Traditional Sake & Rice Measuring)	95.0g

The Global Diversity of Volumetric Cup Standards

One of the most common causes of baking failure when cooking from international recipes or food blogs is assuming that "1 cup" represents a universal volume. In reality, five distinct cup volume standards are currently used worldwide.

In the United States, home recipes use the US Customary Cup standardized at 8 US fluid ounces (236.588 milliliters). However, US nutrition labeling regulated by the FDA uses the US Legal Cup, standardized at exactly 240 milliliters.

In Australia, New Zealand, the United Kingdom, Canada, and South Africa, modern recipes use the Metric Cup, standardized at exactly 250 milliliters. A metric cup is 5.7 percent larger than a US customary cup. If an American baker uses a US cup for an Australian recipe requiring 4 metric cups of flour, they will under-measure flour by nearly 54 grams.

UK Imperial & Japanese Cup Volume Discrepancies

Historical British cookbooks published prior to metrication in 1975 use the UK Imperial Cup, defined as half an Imperial pint or 10 Imperial fluid ounces (284.13 milliliters). The Imperial cup is 20 percent larger than the US customary cup. Using a US cup for a vintage British recipe results in severe under-measurement of all ingredients.

In Japan, modern kitchen measuring cups are standardized at 200 milliliters (known as the Japanese Metric Cup). However, traditional Japanese rice cookers and sake recipes use the traditional "Gō" cup, standardized at 180.39 milliliters (approx 6.1 US fl oz).

This is why the plastic measuring cup included inside Japanese electric rice cookers is smaller than a standard US measuring cup. Filling a 180 mL rice cup with water provides the exact water-to-rice ratio intended by Japanese appliance manufacturers.

How to Adapt International Recipes Safely

When baking from international sources, first identify the country of origin to determine which cup standard applies.

If executing an Australian or British metric recipe (250 mL cup) using US measuring cups (236.59 mL), add 1 extra tablespoon plus 1 teaspoon of ingredient for every cup specified in the recipe to bridge the 13.41 mL gap.

Alternatively, eliminate volume discrepancies entirely by converting international cup recipes into metric scale mass in grams using our interactive site converters. Weighing ingredients on a digital scale guarantees perfect baking regardless of recipe origin.

Ingredient Weight Impact Across International Cup Standards (All-Purpose Flour & Sugar)

Cup Standard Designation	Milliliter Capacity	AP Flour Mass (g)	Granulated Sugar Mass (g)	Unsalted Butter Mass (g)	Pure Water Mass (g)
Japanese Cup	200.0 mL	105.7g	169.1g	191.9g	200.0g
US Customary Cup	236.6 mL	125.0g	200.0g	227.0g	236.6g
US Legal Cup (FDA)	240.0 mL	126.8g	202.9g	230.3g	240.0g
Metric Cup (Commonwealth)	250.0 mL	132.1g	211.3g	239.9g	250.0g
UK Imperial Cup (Vintage)	284.1 mL	150.1g	240.2g	272.7g	284.1g

Practical Consequences: What Happens If You Get It Wrong

Avoid these common pitfalls to protect your baking results and food safety.

Using US Cups for Australian Metric Recipes

US cups (236.59 mL) are 5.7% smaller than Metric cups (250 mL). In a 4-cup flour recipe, this under-measures flour by 54 grams, making cake batters overly wet and runny.

Using US Cups for Vintage UK Imperial Recipes

Imperial cups (284.13 mL) are 20% larger than US cups. Using a US cup under-measures ingredients by one-fifth, destroying recipe balance.

Using Standard US Cups to Measure Water for Japanese Rice Cookers

Japanese rice cookers expect a 180 mL Gō cup. Using a 236.59 mL US cup adds 31% excess water, turning rice into mushy porridge.

Confusing US Customary Cups with US Legal Nutrition Label Cups

US Legal cups (240 mL) used on food packaging differ slightly from 236.59 mL recipe cups. While minor for cooking, it impacts exact calorie logging.

Frequently Asked Questions

Is a UK cup the same size as a US cup?

No. Modern UK recipes use the 250 mL Metric cup (5.7% larger than US 236.59 mL cups), while vintage UK recipes use the 284.13 mL Imperial cup (20% larger).