Converting Between U.S. and Metric Measurement Systems

The metric system used throughout the rest of the world is a decimal system, meaning that it is based on multiples of ten. The gram is the basic unit of weight, the liter the basic unit of volume, and the meter the basic unit of length. Prefixes added to the basic units indicate larger or smaller units.

The U.S. system uses ounces and pounds to measure weight, and teaspoons, tablespoons, fluid ounces, cups, pints, quarts, and gallons to measure volume. Unlike the metric system, the U.S. system is not based on multiples of a particular number, so it is not as simple to increase or decrease quantities. Rather, the equivalencies of the different units of measure must be memorized or derived from a chart.