Jigger

A "jigger" can either be a measuring device used by bartenders, or a unit of measure (typically 1.5 ounces).

As a measuring device, the typical jigger is a metal, hour-glass shaped receptacle, which can measure two different amounts. The larger end would measure a "jigger" (1.5 ounces) and the smaller end would measure a "pony" (1 ounce).

Ounces versus Milliliter

For cocktail recipes measured in "ounces" it is common to use 1/4 ounce increments, which is how virtually all jiggers designed. Outside of the US, where metric measurements (instead of "Imperial") are more common and most recipes are listed in milliliters (ml). Recipes listed in ml will usually use measures in increments of 5ml, which doesn't quite match up to 1/4 ounce increments, so simply doing a conversion from one to the other doesn't always produce appropriate results. One of these days, the US will join the rest of the world and switch to metric.

Here is a comparison of 1/4 ounce increments to their milliliter equivalent.

oz	ml
1 tsp	5
1/4	7.5
1/2	15
3/4	22.5
1	30
1 1/4	37.5
1 1/2	45
1 3/4	52.5
2	60

oz	ml	versus	ml	oz
1 tsp	5		5	1 tsp
1/4	7.5		10	1/3
1/2	15		15	1/2
3/4	22.5		20	2/3
1	30		25	5/6
1 1/4	37.5		30	1
1 1/2	45		35	1 1/6
1 3/4	52.5		40	1 1/3
2	60		45	1 1/2
			50	1 2/3
			55	1 5/6
			60	2

External Links

• Design For A Jigger (C. P. Dungan, 1893) (Google Patents)