The tape measure is one of the most important tools in any toolbox, whether you’re a professional tradesperson or a weekend DIYer. Even though it looks easy, reading a tape measure correctly means knowing how to read different types of measurements and markings. This post will show you how to read the different measurement units on a tape measure, so that you can be more accurate when doing projects.
Understanding Inch Measurements
When you look at a tape measure, you’ll see a series of marks in different lengths. The longest marks show whole inches and usually have numbers next to them. Between these whole-inch marks are smaller lines representing fractions of an inch. In the US, most tape measures divide each inch into 16 equal parts, called sixteenths.
The half-inch mark is the longest line between the inch marks. This is followed by the quarter-inch mark, and then eighth-inch mark. The shortest lines show measurements in sixteenth of an inch. To read a measurement, find the whole inch mark before your endpoint and then count the fractional marks until you reach the endpoint.
For example, if your measurement is on the third mark after the 2-inch line, and you’re using a tape measure with sixteenth-inch divisions, your measurement would be 2 and 3/16 inches. Remember to simplify fractions whenever possible. If your measurement falls on the fourth mark (4/16), you would express this as 1/4 inch.
Reading Feet on a Tape Measure
Most tape measures used in construction show both inches and feet. The foot markings are usually the most noticeable, with special markers every 12 inches. A handful of tape measures use larger numbers, different colors (often red), or special symbols to mark each foot.
When you read measurements longer than 12 inches, you’ll notice that the inch markings continue to go up rather than starting over at 1. However, there are some tape measures that include smaller secondary numbers to show you the foot-and-inch measurement. For example, at the 25-inch mark, you might see a smaller “2′-1″” notation, indicating 2 feet and 1 inch.
Reading Millimeters on a Tape Measure
Metric tape measures use a different system that is based on millimeters and centimeters. When reading millimeters, you’ll see that each centimeter is divided into 10 equal parts. Each small mark represents one millimeter. The millimeter marks are the smallest markings on a metric tape measure.
To read a millimeter measurement, find the biggest centimeter mark before your endpoint, then count the number of millimeter marks after it. For example, if your measurement falls 8 marks after the 6-centimeter mark, your measurement would be 6 centimeters and 8 millimeters, or 6.8 centimeters.
Reading Centimeters on a Tape Measure
On a metric tape measure, the centimeters are marked by numbered lines. As each centimeter equals 10 millimeters, conversions are pretty easy using this decimal-based system. The centimeter marks are the longest lines on a metric tape measure, just like inch marks are the longest on an imperial tape measure.
To read centimeters, find the numbered mark that is closest to your measurement point without going past it. Then count the millimeter marks after it to get your measurement. For example, if your measurement is at the 7-centimeter mark plus 5 millimeter marks, your measurement would be 7.5 centimeters.
Reading Meters on a Tape Measure
Longer metric tape measures include meter markings. Since a meter is equal to 100 centimeters, every 100-centimeter mark represents one meter. To make these meter marks stand out on a metric tape measure, they are often highlighted with special colors or symbols.
Some metric tape measures mark every 10th centimeter in red or in some other way to make it easier for you to identify larger measurements. When reading meters, find the largest meter mark before your endpoint, then read the remaining centimeters and millimeters. For example, a measurement of 1 meter, 34 centimeters, and 5 millimeters would be written as 1.345 meters in decimal form.
Tips for Accurate Measurements
• Always make sure that the “zero” end of the tape measure is lined up with the edge of what you’re measuring.
• For any inside measurements, like inside a window frame, you need to add the width of the tape measure case to get the correct measurement.
• When measuring, you need to keep the tape straight and taut to avoid sagging. Failing to do this leads to inaccurate measurements.
• Some tape measures include both imperial and metric measurements, but these can be harder to read because they are so cluttered. Consider using measuring tapes for each system when you need precise measurements.
Learning how to read a tape measure in different measurement systems will improve your project’s accuracy. No matter if you’re working with imperial or metric measurements, knowing what the markings on your tape measure means will help you get the right results every time.
