How to Read a Ruler

How to Read a Ruler

Have you had to measure something, but you didn’t know how the measurements actually worked? Reading a Ruler is important when learning the value of measuring things when building, creating, or figuring out a math problem.

Knowing the difference between rulers is important when measuring correctly and appropriately.

English Ruler

english ruler

An English ruler is divided into 12 parts that are each an inch apart. A total of 12 inches equals 1 total foot. Each inch is divided into 15 markings, which equal 16 parts with every inch.

This means that each marking lengthens the measurement by 1/16. Reading this ruler left to right is imperative to get the correct measurement.

  • Inch Markings

ruler inch marking

When measuring something using inches, place the item on the far lefthand side of the ruler. If the item ends next to a number on the ruler (ex. 6 inches), then that item is 6 inches long.

  • Half-Inch Markings

half inch ruler

The markings for half an inch are the second longest lines that are on the rule itself. This marking comes midway between the inch markings on each side, and spans the entire length of the ruler. There are a total of 24 half-inch markings on each English ruler.

  • One-Fourth Inch Markings

ruler inch fourth

In between each of the half-inch lines are the one-fourth inch lines. These markings are at the 1/4, 1/2, 3/4, and 1 inch lines. Even though the 1/2 and 1 inch lines already have their own number, the 1/4 lines are still apart of this measurement process. This adds up to 48 1/4 inch total markings across the 12 inch ruler.

  • One-Eighth Inch Markings

one eighth inch ruler

The 1/8 inch measurements are the smaller lines in between the 1/4 inch marks. In a total inch, the 1/8 markings total 96 markings on a 12 inch ruler.

  • One-Sixteenth Inch Markings

one sixteenth ruler inch

Not all English rulers have 1/16 markings, but if they do there are 192 lines on the ruler. The 1/16 lines are the smallest on a ruler, and each marking goes up 1/16 at a time.

Metric Ruler

metric ruler

A Metric ruler uses a different measurement than an English ruler. Instead of inches, this measurement uses centimeters and the smaller measurements of millimeters. Each metric ruler should have 30 total centimeters to make it official. Like the English ruler, measure things from left to right.

  • Centimeter and Millimeter Markings

centimeter ruler

The longest markings are centimeter lines, and the smaller lines are millimeter markings. 10 total millimeters equal 1 centimeter. There are a total of 300 millimeter markings on each metric ruler.

Understanding the difference between an English ruler and a Metric ruler is important when measuring appropriately. Knowing the difference will help you measure things appropriately.

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