How to Read a Standard Ruler in Metric Units

The standard English ruler, or imperial ruler, as it is also known, is calibrated into inches. Each inch is then broken down into smaller units: 1/2 inch, 1/4 inch, 1/8 inch, and 1/16 inch. Before the metric system, the standard way to measure length was in feet and inches. Reading a standard ruler in metric units is easy as long as you know the correct conversion rate.

• 1

  Type 2.54 into your calculator. One inch is equal to 2.54 cm. This is the basic conversion unit from which all other calculations can be performed.

• 2

  Divide 2.54 by 16. The answer is 0.15875. So 1/16 inch---the lowest calibration on a standard ruler---is equal to 0.15875 cm, or, roughly, 1.6 mm (there are 10 millimeters to a centimeter).

• 3

  Multiply 2.54 by 12. The answer is 30.48. This means that 30.48 cm is equal to 12 inches, or a "foot." Most standard rulers are 1 foot long.

• 4

  Perform various multiplications and divisions to get the hang of converting standard ruler measurements to metric units.