The easiest method to use when converting Metric units to English units is understand what the basis of each unit. Metric units are based on ten (10). To determine the next unit is to multiply the previous by ten. If one (1) centimeter is equivalent to 10mm, then 1 Meter is equivalent to 100 cm (10 x 10=100) and 1 Kilometer (100 x 10= 1000) is 1000m. Assuming you already know the English units, .