What is the usual ounce capacity of a jigger?

The usual ounce capacity of a jigger is one and one-half ounces, or 1.5 U.S. fluid ounces. A jigger is a small measuring tool used by bartenders to portion spirits and other liquid cocktail ingredients accurately.

Many modern jiggers are double-ended, with a larger 1.5-ounce cup on one side and a smaller 1-ounce cup on the other. The smaller measure is often called a pony. This design lets a bartender make common cocktail proportions quickly without using a separate measuring cup.

The word can refer either to the tool or to the amount it measures. In everyday American bartending, “a jigger of whiskey” generally means about 1.5 fluid ounces, equivalent to approximately 44 milliliters; recipes often round that to 45 milliliters. However, capacities are not universal. Some jiggers hold 1 ounce, 2 ounces, or have multiple internal markings, and legal serving sizes differ between countries.

A jigger should not be confused with a standard drink. A standard drink measures the amount of pure alcohol, while a jigger measures liquid volume. The alcohol content therefore depends on the spirit’s strength.