Cup (cup)

A US customary unit of volume equal to 8 fluid ounces

The Cup (cup) is a unit of volume that developed alongside the needs of commerce, cooking, and chemistry. Volume measurement was crucial for trade in liquids like wine, oil, and grain, leading to a profusion of regional standards that varied even between neighboring towns. The metric system's liter and its multiples brought standardization to most of the world, though the US customary volume system of cups, pints, quarts, and gallons persists in American cooking and everyday use. The Cup belongs to one of these traditions.

Accurate volume measurement is critical in engineering, science, commerce, and everyday life. Using the correct unit and applying conversions precisely prevents errors that can be costly or dangerous in professional applications.

Conversion Table

UnitSymbol1 cup =
LiterL0.236588 L
MillilitermL236.588 mL
Gallon (US)gal0.0625 gal
Fluid Ouncefl oz8 fl oz
Tablespoontbsp15.9999 tbsp
Teaspoontsp48 tsp
Pintpt0.5 pt
Quartqt0.25 qt

Conversions Involving Cup

Common Uses of the Cup

  • Cooking — measuring liquid ingredients in recipes
  • Fuel and fluid systems — sizing tanks, reservoirs, and pipelines
  • Chemistry — measuring solutions and reagents in laboratory procedures
  • Medicine — prescribing and administering liquid medications
  • Environmental science — measuring water discharge and rainfall volume

Did You Know?

The liter was originally defined in 1795 as the volume of one kilogram of water at 4°C — creating a convenient link between mass and volume for water. The Cup is part of the broader volume measurement story that connects everyday cooking to industrial fluid handling.