Cups to milliliters volume measurement units conversion factors are listed below. To find out how many milliliters in cups, multiply by the right factor or simply use the converter if converting from US cups. 1 Cup [US] = 236.588237 Milliliters. 1 Cup [Metric] = 250 Milliliters. Cup is a volume unit and used mostly in cooking to measure liquid and bulk, dry foods. There is no international standard for cup sizes but mostly US customary and metric cups are used. Milliliter is a volume unit in metric system. The abbreviation is ml.