A ruler is a common measuring tool used to measure and draw straight lines. It is typically a long, flat, and narrow strip made of materials like wood, plastic, or metal. Rulers are marked with units of measurement, such as inches or centimeters, along their length, allowing for precise measurement and drawing. Some have specialized markings for specific applications like architectural or engineering scales. Rulers come in various lengths, from small pocket-sized rulers to larger ones used in drafting and technical drawing. The most common rulers are marked with both imperial (inches) and metric (centimeters) measurements, enabling measurement in different systems. 


Reading a ruler is an important life skill that is one of the bases of a technical drawing. In America we mainly use the imperial system of measurement which means we measure in inches and feet while the rest of the world uses the metric system comprised of meters. For now I am going to focus on how to read a ruler made up of inches and what all those tick marks mean. So to start, a foot, which is the normal length of a ruler is made up of 12 inches. An inch can be broken up into fractional parts, normally the smallest being a 16th but a 32nd is also commonly used. But what does that mean?

Let's break it down step by step:

Remember to take measurements carefully, ensuring that the object is flat against the ruler for accurate readings. Practice using the ruler on various objects to enhance your measurement skills and familiarize yourself with both inch and metric systems. With practice, reading a ruler will become second nature, empowering you with precise measuring abilities.

Breaking Down the Inch

1 inch broken down to 16ths

When you look at a ruler the whole numbers represent whole inches. While the tick marks of varying lengths correspond to fractions of an inch. The longest tick mark splits the inch into two halves and represents 1/2 an inch. When you split a half an inch by half again you have 1/4 of an inch, breaking the inch into four parts. When you add two fourths together they add up to one half. You will notice that there is also 3/4 represented on the ruler below.  This tick mark shows three quarters of an inch, one quarter more than half an inch. 

This pattern continues, splitting the previous fraction in half to get the next fractional value represented on the ruler. Half of a fourth is an eighth, half of an eighth is a sixteenth, and so on. You can count the tick marks to get the measurement you are looking for, but it is a good idea to start to recognize the tick mark lengths so you know what fraction of an inch you are working with. Also, you will never have an even numerator, if you do that means you can simplify down to a larger fractional denominator. Below is a ruler with multiple colored marks, find the measurements for each and don't forget about the whole number inches.

Ruler Practice

Find the measurements of all the colored marks below

Ruler reading practice

Paper Ruler

For almost any Tech. Ed. class, mastering one essential skill will be paramount: ruler reading. This skill is indispensable in everyday industry practices, serving as the universal language for communicating ideas and facilitating the construction process.

Steps for the Paper Ruler:

1 inch broken down to 16ths