The measure that is equivalent to 2 standard bottles of champagne is known as a magnum. It contains 1.5 liters of champagne, which is equivalent to the volume of two standard 750ml bottles. Magnums are often used at special occasions and large gatherings as they provide enough champagne for a group of people to enjoy. They are also known to age better due to the larger volume, allowing the champagne to mature at a slower rate.