Cup (unit)
From Wikipedia, the free encyclopedia
The cup is a unit of measurement for volume, used in cooking to measure bulk foods, such as chopped vegetables (dry measurement), and liquids (fluid measurement). It is in common use in many countries, especially those that were part of the British Empire, including the United States and most members of the Commonwealth of Nations, and nations that were influenced by them, such as Japan. The cup is not commonly used in the United Kingdom or the rest of Europe.
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[edit] Definitions
There is no internationally agreed standard definition of the cup, which ranges in volume between 200 and 250 millilitres.[1] Because the cup sizes generally used in the many Commonwealth countries and the United States differ only by about 13 ml (0.5 fl oz), the respective measures are close enough for cooking.
[edit] Commonwealth of Nations
- Imperial cup
- The imperial cup was defined as half an imperial pint. The unit is no longer in use.
1 imperial cup = 0.5 imperial pints = 10 imperial fluid ounces = 284.130625 millilitres ≈ 284 ml ≈ 19 international tablespoons[2][3] ≈ 14¼ Australian tablespoons[4] ≈ 1.2009 U.S. customary cups ≈ 9.6076 U.S. customary fluid ounces
- Metric cup
- In Australia, Canada, New Zealand one cup is defined as 250 millilitres. This is the commonly used cup.
1 metric cup = 250 millilitres = 16⅔ international tablespoons = 12½ Australian tablespoons ≈ 8.7988 imperial fluid ounces ≈ 8.4535 U.S. customary fluid ounces
[edit] United States
- United States customary cup
- United States customary cup is defined as half a U.S. pint.
1 U.S. customary cup = 0.5 U.S. pints = 8 U.S. fluid ounces = 236.5882365 millilitres ≈ 237 ml ≈ 15⅔ international tablespoons[5] ≈ 11¾ Australian tablespoons ≈ 0.8327 imperial cups ≈ 8.3267 imperial fluid ounces
- United States "legal" cup
- The cup currently used in the United States for nutrition labelling is defined in United States law[6] as 240 ml.[7][8]
1 U.S. "legal" cup = 240 millilitres = 16 international tablespoons = 12 Australian tablespoons ≈ 8.1154 U.S. customary fluid ounces ≈ 8.4468 imperial fluid ounces
[edit] Japan
- Japanese cup
- The Japanese cup is currently defined as 200 ml.
1 Japanese cup = 200 millilitres ≈ 7.0390 imperial fluid ounces ≈ 6.7628 U.S. customary fluid ounces
- Gō
- The traditional Japanese cup, the gō, is approximately 180 ml. 10 gō make one shou, the traditional flask size, approximately 1.8 litres. Sake is typically sold by both the cup (180 ml) and flask (1.8 litre) sizes. The cup size used for measuring rice is the traditional size of 180 ml. (For example, a 10-cup rice cooker has a capacity of 1.8 litre or 1 shou.)[citation needed]
1 gō = 2401/13310 litres[9] ≈ 180.39 millilitres ≈ 180 ml ≈ 6.3489 imperial fluid ounces ≈ 6.0997 U.S. customary fluid ounces
[edit] Using volume measures to estimate mass
In metric regions, cooking recipes normally state any liquid volumes larger than a few tablespoons in millilitres, the scale found on most measuring cups worldwide. Non-liquid ingredients are normally weighed in grams instead, using a kitchen scale, rather than measured in cups. Some recipes in Europe use the decilitre (1 dl = 100 ml) as a cup-like measure. For example, where an American customary recipe might specify "1 cup of sugar and 2 cups of milk", a metric recipe might specify "200 g sugar and 500 ml of milk" (or ½ litre or 5 decilitres). Conversion between the two measures must take into account the density of the ingredients.
| Volume to mass conversions for some common cooking ingredients | |||||||
|---|---|---|---|---|---|---|---|
| ingredient | density g/ml[10] | metric cup | imperial cup | U.S. customary cup | |||
| g | oz | g | oz | g | oz | ||
| water[11] | 1[12] | 249–250 | 8.8 | 283–284 | 10 | 236–237 | 8.3[13] |
| granulated sugar | 0.8[14] | 200 | 7.0 | 230 | 8.0 | 190 | 6.7 |
| wheat flour | 0.5–0.6[14] | 120–150 | 4.4–5.3 | 140–170 | 5.0–6.0 | 120–140 | 4.2–5.0 |
| table salt | 1.2[14] | 300 | 10.6 | 340 | 12.0 | 280 | 10.0 |
[edit] Notes and references
- ^ Note also that cup sizes in recipes do not necessarily equate serving sizes for beverages. For example, a cup of brewed coffee in the U.S. is traditionally only 6 U.S. fluid ounces (180 ml).
- ^ In the absence of measuring cups, tablespoons can be used for volume measurement.
- ^ The term international tablespoon as used in this article refers to the 15 ml (~½ fl oz) tablespoon used in most countries.
- ^ The Australia tablespoon is defined as 20 ml (~⅔ fl oz)
- ^ Note: 1 U.S. customary cup = 16 tablespoons exactly using the old U.S. customary tablespoon of ½ U.S. fl oz.
- ^ (21 CFR 101.9 (b) (5) (viii)
- ^ U.S. Government Printing Office—Electronic Code of Federal Regulations
- ^ U.S. Food and Drug Administration—Guidelines for Determining Metric Equivalents of Household Measures
- ^ by 1891 definition
- ^ One gram per millilitre is roughly equivalent to one avoirdupois ounce per fluid ounce or, more specifically:
- 1 g/ml ≈ 1.002 av oz/imp fl oz
- 1 g/ml ≈ 1.043 av oz/U.S. fl oz
- ^ 1 g/ml is a good rough guide for other water-based liquids such as milk (the density of milk is about 1.03–1.04 g/ml).
- ^ The density of water ranges from about 0.96 to 1.00 g/ml dependant on temperature and pressure. The table above assumes a temperature range 0–30°C (32–86°F). This variation is not generally a concern when cooking.
- ^ Since an imperial cup of water weighs approximately 10 avoirdupois ounces and five imperial cups are approximately equal to six U.S. cups, one U.S. cup of water weighs approximately 8⅓ avoirdupois ounces.
- ^ a b c L. Fulton, E. Matthews, C. Davis: Average weight of a measured cup of various foods. Home Economics Research Report No. 41, Agricultural Research Service, United States Department of Agriculture, Washington, DC, 1977.
ko:컵 (단위) ja:計量カップ
