What bottle of champagne is the equivalent to 20 bottles?

There's no single bottle of champagne that's equivalent to 20 bottles in volume. You're likely thinking about Jeroboam, which is a large champagne bottle that holds 3 liters, the equivalent of 4 standard champagne bottles (750ml each).

Here's a breakdown of champagne bottle sizes:

* Standard Bottle: 750 ml (also known as a "Magnum")

* Magnum: 1.5 liters (equal to 2 standard bottles)

* Jeroboam: 3 liters (equal to 4 standard bottles)

* Rehoboam: 4.5 liters (equal to 6 standard bottles)

* Methuselah: 6 liters (equal to 8 standard bottles)

* Salmanazar: 9 liters (equal to 12 standard bottles)

* Balthazar: 12 liters (equal to 16 standard bottles)

* Nebuchadnezzar: 15 liters (equal to 20 standard bottles)

Therefore, a Nebuchadnezzar holds the equivalent of 20 standard champagne bottles.