Rulers for School

A ruler, also known as “rule” or “line gauge”, is a thin rectangular measuring device that has straight edges and length measurement markings, equidistant & parallel lines with numbers, along the edge. Depending on the rigidity, lightweight or how often will be used, rulers can be made out of different materials such as metal, wood or plastic. In our case, the rulers you will find here are made to be printed on sheets of paper.

When it comes to accuracy the best material for a ruler has to be steel which is durable and rigid. These type of rulers for precision measurements may be have to be certified by NIST (National Institute Of Standards and Technology), to be more accurate, by the Dimensional Metrology Group of the US government.

Like most rulers, they are mostly used in school for math, geometry and technical drawing, as well as the engineering and construction, carpentry, sewing, printing and many more other industries. These type of rulers have different names such as plastic or wooden rulers, architects scales, carpenters rules, seamstress tapes, measuring tapes and yardsticks. Rulers can vary in length and systems, like the 6” and 12” (in or inches) ones, they are using imperial system. The 100 mm (10 cm), 200 mm (20 cm), 300 mm (30 cm), mm – millimeters, cm – centimeters rulers are using the metric system.

Reading Ruler Measurements – Metric System

In the metric system, the meter is the the standard unit for measurement. Most measurements in science class are done using a smaller scale then a meter which is either centimeter (cm) or millimeter (mm). On a metric ruler, each small mark (line) represents a mm. The bigger lines with the numbers make up the centimeters. Ten lines or millimeters make up a centimeter. Each line (1 mm) on a metric ruler represents .10 of a centimeter.

How to Read Ruler Measurements

Measure of Lengths – Conversion Table

Millimeters (mm) to Centimeters (cm) to Decimeters (dm) to Meters (m) Conversion Chart
mm	cm	dm	m
1	0.1	0.01	0.001
10	1	0.1	0.01
100	10	1	0.1
1000	100	10	1

So one millimeter (1 mm) is one one-thousandth of a meter (1/1000 m). One centimeter (1 cm) is one one-hundredth of a meter (1/100 m). One decimeter (1 dm) is one-tenth of a meter (1/10 m). Therefore to convert millimeters until meters divide the number by 10 to get the correct value.

Measurements on an Inch Ruler – Imperial System

How to read a ruler in inches? First of all, the lines on a standard inch ruler represent the fractions of an inch. The markings on an inch ruler from the beginning (0”) to the 1” mark are: 1⁄16”, 1⁄8”, 3⁄16”, 1⁄4”, 5⁄16”, 3⁄8”, 7⁄16”, 1⁄2”, 9⁄16”, 5⁄8”, 11⁄16”, 3⁄4”, 13⁄16”, 7⁄8”, 15⁄16”, and 1”. Let’s say that if the measurement is past the 1″ mark, simply use the number on the ruler and add the fraction, for example, if you’re two ticks past the 5” mark then the measurement is 5*1⁄8”.

How to Read a Ruler in Inches

The big and red lines represent a full inch and the distance between them is one inch.
The smaller darker lines represent the sixteenth-inch mark and the distance between them and the other bigger lines is 1⁄16”. These lines on the ruler above are marked as 1/16, 3/16, 5/16, 7/16, 9/16, 11/16, 13/16 and 15/16.
The slightly bigger blue lines represent the eighth-inch mark and the distance between them and the bigger ones is 1⁄8”. These lines on the ruler above are marked as 1/8, 3/8, 5/8 and 7/8.
The mid-sized green lines represent the quarter-inch mark and the distance between them and the bigger ones (1” and 1⁄2”) is 1⁄4”. These lines on the ruler above are marked as 1/4 and 3/4.
The large yellow line is the half-inch mark and the distance between an inch mark and it is 1⁄2”.

Conversion Table – Ruler Fractions to Decimal & Millimeters

Fraction, Decimal, and Millimeter Equivalent Measurements
Fraction	Decimal	Millimeters
1⁄16”	0.0625	1.5875
1⁄8”	125	3.175
3⁄16”	0.1875	4.7625
1⁄4”	0.25	6.35
5⁄16”	0.3125	7.9375
3⁄8”	375	9.525
7⁄16”	0.4375	11.1125
1⁄2”	0.5	12.7
9⁄16”	0.5625	14.2875
5⁄8”	625	15.875
11⁄16”	0.6875	17.4625
3⁄4”	0.75	19.05
13⁄16”	0.8125	20.6375
7⁄8”	875	22.225
15⁄16”	0.9375	23.8125
1”	1	25.4

Millimeter (mm) Rulers

On most standard metric rulers, each small line (marking) represents a millimeter (mm). In the list bellow you will find some millimetre ruler templates that have correct markings and can be print out.

Check out other mm rulers that come in different colors, patterns and sizes.

Centimeter (cm) Rulers

Ten millimetres make up a centimeter. On a metric ruler they are represented with a larger mark and number. Our list of printable templates contain a variety of rulers that have different markings, textures and forms.