How to Read a Standard Ruler in Metric Units

Converting standard measures to metric units is a matter of simple mathematics

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.

Things You'll Need

• Standard ruler
• Calculator

Instructions

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.

References

• RS Innovative: The Ruler Game

Resources

• Science Made Simple: Conversions