Convert U.S. customary units to metric measurements using a metric conversion equation chart. To convert miles to kilometers multiply the original mile amount, for example three miles, by 1.61, the number called for in the metric conversion equation. The final number, in this example 4.83, will produce the number of kilometers. To use a chart such as this you will plug the number into each formula, which will involve plugging the U.S. customary amount into an equation in order to get the metric amount.
Convert into the metric system using a printable metric conversion chart. This type of chart, hosted by metricconversioncharts.org, offers a single U.S. measurement unit and the equivalent in metric measurement. To use this chart simply multiply both the U.S. unit and the metric unit by the amount you would like to convert. For example, if you want to convert two U.S. gallons to liters simply multiply the gallon measurement by two so that you will have two gallons. Then multiply the liter side by two. The liter side is originally about 3.78 so after multiplying by two the final answer will be 7.56. So two U.S. gallons equals 7.56 liters.
Use an online automatic conversion service, like the one available at onlineconversion.com. If you are not making a simple calculation between U.S. measurements and the metric system, a sure way to get the correct converted measurement is to plug in the units you want to convert into an online converter. You will input the original measurement to be converted, pick which system the original measurement is in, and finally pick which system you would like the measurement to be converted to. The measurement ratio will be displayed directly below the converter. This service gives conversions for obscure worldwide measurements.