<P> In the United States, the size of these bottles is usually 7 U.S. fl oz (207 ml), and are similar to the size of original Coca - Cola and Pepsi Cola bottles . The term pony dates to the 19th century, and is due to the diminutive size, being used earlier for a pony glass, and similarly for a pony keg . The best - known brands of ponies are Rolling Rock (pony introduced 1939?) and Miller High Life (pony introduced 1972), and the 7 oz size of Rolling Rock likely contributed to the standardization on this size . Other major brands (Budweiser, Coors, Miller) are also regionally available in 7 oz bottles; these were introduced in the early 1970s, around the time of Miller High Life being so - packaged . More recently, Bud Light Lime has started to be sold in ponies, called "Limeys". </P> <P> The popularity of Rolling Rock ponies has led to the folk etymology that "pony" is from the Rolling Rock horse logo . This is incorrect: the term "pony of beer" in the United States predates Rolling Rock (introduced 1939) by over 50 years, and advertising for Rolling Rock from the 1950s uses the term "pony bottle" generically, stating "...Rolling Rock is the Largest Selling 7 oz . Pony Bottle of Premium Beer in Pennsylvania". </P> <P> Among Mexican beers, Corona sells ponies, branded as Coronita, from the Spanish diminutive - ita . </P> <P> In Australia, a limited range of beers are available in a 250 ml (8.8 imp fl oz; 8.5 U.S. fl oz) bottle, nicknamed a throwdown or grenade . </P>

How many liters is a 6 pack of beer