# How to Read a Tape Measure

By: HowStuffWorks.com Contributors  |

Tape measures are one of the most commonly used measuring tools. Everyone from contractors and tailors to tradesman and everyday homeowners use measuring tapes to get exact measurements of every kind.

While it might seem like a simple tool, many tape measure markings are available in both the metric system and imperial measurements, so it's important to know how to read a tape measure to ensure you get a precise reading and accurate measurement. As the old saying goes: "Measure twice, cut once."

Contents

## Parts of a Tape Measure

Before we explain how to read a tape measure, let's talk about the parts of a tape measure. Though the parts might not look exactly the same on every tape measure, most are pretty basic and fall into these few categories:

• Blade: the "tape" in a tape measure that has the measurements printed on it
• Metal hook: the metal piece at the end of the tape that you can use to grab or hold material you're measuring
• Hook slot: a hole in the hook; you can use the hook slot to clip the tape onto a nail or screw while you're measuring
• Case/housing: plastic or metal case that holds the measuring tape
• Lock: a sliding lock on the housing that prevents the tape from retracting in when you're measuring
• Belt clip: a metal piece on the housing that allows you to clip the tape to your belt or tool bag

## How to Read a Tape Measure in Inches and Feet

Most tape measures you'll see in the United States have the boldest markings in inches and feet. So when looking at the tape starting at the hook, there will be number markings for every inch, as well as number markings for every foot on the top line of the tape.

Once the tape measure goes past 1 foot in length, the inch markings on the top line increase to 13, 14, 15, etc. instead of starting over at 1. Some measuring tapes also have additional smaller numbers that equate with the last foot mark. For example, the tape measure might designate 22 inches equal 1 foot, 10 inches.

Let's look at how to actually read a tape measure in inches:

1. When reading a tape measure in inches, mark the closest full inch to the end point you're measuring. Note how many indicator lines remain. Add those fractions of an inch remaining to the whole inches to get your total measurement.
2. To read an inch, look for the large numbers in bold, black type. They refer to the longest markings along the edge of the tape.
3. To read 1/2-inch measurements, locate the second-longest mark between the longer inch marks. For 1/4-inch marks, look halfway between the 1/2-inch marks.

Keep in mind when you're learning how to read a tape measure in inches, the majority of tapes will divide each inch into 16 sections. That means you can get accurate measurements within 1/16-inch, including a half-inch mark, a quarter-inch mark, an eighth-inch mark and a sixteenth-inch mark.

## How to Read a Tape Measure in Millimeters

Reading a tape measure in millimeters is a bit different from reading a tape measure in inches.

Metric tape measures feature 10 marks to every 1 centimeter. The smallest marks on a tape indicate 1 millimeter or 1/10th of a centimeter. The bold markings on a metric tape measure indicate centimeters.

Let's look at how to actually read a tape measure in millimeters:

1. To read a metric measuring tape, find the nearest whole centimeter to the end point you're measuring. Note how many indicator lines remain to see how many millimeters are left over.
2. Add those to the whole centimeters, using a decimal. (For example, if you measure 15 whole centimeters and have 8 millimeter marks left over, your total measurement is 15.8 centimeters.)

## General Tape Measure Tips

Using a measuring tape properly is essential to getting an accurate measurement. Here are a few tips on how to make sure you're using your tape measure and reading those special markings correctly.

• To get the most exact measurement, make sure your tape measure is evenly aligned with what you're measuring.
• If you need extra accuracy, do what's called "burn an inch," which means start your measurement at the 1-inch mark instead of using the hook on the tape. Just remember to subtract that extra inch from your total measurement.
• Speaking of hooks, a properly functioning hook is designed to move slightly based on the thickness of the metal, usually about 1/16-inch.
• If the hook on your tape measure is bent or damaged, you won't get exact measurements.
• Be careful when retracting a tape measure. Allowing it to snap back can damage the tape. Instead, retract the tape back in slowly.
• Some tape measures have small, black diamonds visible every 19 3/16 inches, which is the same spacing used for engineered floor joists in new construction.
• If you're using multiple tapes on the same job, calibrate them to ensure your measurements on the job are exact.