Reading a ruler might seem like a skill learned so long ago it comes naturally, but the truth is many people read rulers incorrectly.Reading a ruler or tape measure is an important skill for construction workers, carpenters, architects, and homeowners. There are a variety of everyday reasons people have for using rulers. If you read yours incorrectly, it can wreak havoc on your project. Learning to read a ruler is an important part of collecting accurate measurements. It is possible to just focus on the inch and half-inch marks on the ruler. You will use the smaller lines for more accurate measurements, but if you just need an approximate measurement, the larger marks will suffice. The key to reading the ruler is to understand what each mark means. There are inch and half-inch marks, as well as quarter, eighth and sixteenth inch intervals.

**Standard Ruler Markings**

Standard rulers are 12 inches and are usually marked with a number at each of the inch intervals. Between the numbers are several vertical lines marking fractions of each inch. The vertical lines vary in length, depending on the interval. For instance, the half inch mark is usually the longest, followed by the quarter and eighth inch. In most cases, anything below the full inch is not marked with a number. When you first learn how to read a ruler, you will likely need to count the lines when measuring. The more familiar you are with using the ruler, the easier it will be to know the measurement with just a glance.

Fractions are an important part of reading a ruler accurately. Exact measurements usually include a fraction of the entire inch. The lines between the numbers show how big the fraction is. Converting the number of lines to an accurate fraction requires a few math skills. Begin by taking the measurement. Let’s say you measure a piece of wood and the length reaches the 5 inch number on the ruler, as well as four of the small lines following the number 5. After taking the measurement, write down the number 5, for the four inches, and 4/16, for the fraction of the inch. This number can then be reduced to a more sensible fraction, which in this case would be 2/8 or 1/4. You get this number by dividing 2 into both the top and bottom numbers of the fraction. Your total measurement is 4 and 1/4 inch.

**Adding Measurements**

If you need to add measurements together, you will need to add fractions. Let’s say you are measuring two pieces of wood to get a total measurement. One piece measures 2 3/16 on the ruler and the other 5 and 4/16. These numbers are added together to equal 7 and 7/16. Remember, you do not add the bottom numbers of a fraction because together, the portions do not equal an entire inch. However, if you were to add slightly different measurements of 2 11/16 and 5 and 7/16, your final measurement would be 7 and 18/16 or 8 and 2/16,so 8 and 1/8. This is because the two sections that are fractions of an inch end up equaling a measurement greater than an inch. This combined number can be further formatted to equal 8 and 1/8.

Measuring with a ruler is easy, once you learn to be accurate and work with fractions. With a little practice, you can be an expert.