How To Read a Tape Measure for Newbies (Updated)

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A tape measure is a portable tool contractors use to measure the size or distance of objects. Accurate measurements are important in building a stable home or creating quality furniture. Units in a tape measure can either be imperial or metric. Find out how to read a tape measure and what to consider when choosing one. 

Types of Tape Measures

Construction workers use either metric and imperial units to get the dimensions of objects. For instance, a sheet of plywood measures 8 x 4 feet or 2440 x 1220 millimeters.  

Imperial tape measures read fractions, inches and feet. There are usually meters, centimeters and millimeters on a tape measure. The most widely used one will typically have all three.

Metric Tape Measure

Most carpenters find it easier to work on numbers divisible by 10. It’s also simpler to convert millimeters to centimeters or meters when comparing three different units. In the metric system, 1000 millimeters equals 100 centimeters or 1 meter. 

Reading a Metric Tape Measure in Centimeters

A metric tape measure often uses whole numbers, so adding, subtracting or dividing figures with different units is straightforward. For example, if a piece of wood has a length of 5 centimeters and a width of 8 millimeters, you can convert 8 millimeters to 0.8 centimeters. The numbers will have one unit for comparison. 

One centimeter is equivalent to 10 millimeters, 2 centimeters is 20 millimeters and so on. You can find the units of a tape measure near the hook. Here, the bottom numbers use millimeter and centimeter units. 

Each mark or part reads 1 millimeter, and 10 lines equal 10 millimeters or 1 centimeter. Similarly, 20 millimeters equates to 2 centimeters. The long line between two whole numbers reads half of a centimeter. 

If you need to find 4.4 centimeters in the tape measure, locate 4 centimeters. To find the decimal unit, count four lines from 4 centimeters and that’s 4.4 centimeters. Alternatively, you can also convert 0.4 centimeters to millimeters, resulting in 4 millimeters. Since each line is 1 millimeter, counting four parts from 4 centimeters will give you 4 millimeters. Now, you have 4.4 centimeters. 

Imperial Tape Measure

America is one of the three nations still using the imperial system. People measure things in inches and feet, such as an 8 x 4 feet plywood sheet. Even though the metric system is the standard in most countries, Americans have used the imperial scale longer.

Using an imperial tape measure is as easy as a metric tape measure. However, dealing with numbers can be challenging because it includes fractions. Examples are 1/2 inch and 1 3/4 inches. When recording sizes, you don’t write 0.5 inches or 1.75 inches. 

Reading an Imperial Tape Measure in Inches

Each mark on an imperial tape is equivalent to 1/32 inch. It means 32 lines make up 1 inch. From 1 inch, the first mark is 1 1/32 inches, followed by 1 2/32 inches or 1 1/16 inches when converted, then 1 3/32 inches and so on. 

The most extended vertical lines before the number represent a whole inch, so you have 1 inch and 2 inches. The second longest vertical line between two whole numbers reads half of an inch. The protruding lines on either side of it are 1/4 inch and 3/4 inch. 

If you need to find 1 1/4 inches from the tape measure, count eight marks from 1 inch since 8/32 inch is equivalent to 1/4 inch.

Measuring Using a Tape Measure

After you’ve mastered reading a tape measure, you can take the dimensions of wood, pipes and other building materials. 

Here are the steps on how to use a tape measure:

1. Hook the end tab on a thing you want to measure. 
2. Pull out the tape until you reach the opposite end of the object. 
3. Push the thumb lock to secure the tape in place.
4. Read the measurement. 
5. Mark your reading or write it on a piece of paper.

Tips for Using a Tape Measure

If you want to take precise measurements, follow these strategies.

1. Keep the tape straight and flat on the object you’re measuring to get an accurate reading.
2. If you’re marking a surface, write “v” instead of a straight line. The pointed part points to the measurement.
3. After using the measuring tape, reel it in slowly. Slamming it back into the case ruins the slide on the hook. 

Avoid These Common Mistakes

Learning how to use a tape measure might seem simple, but even seasoned DIYers make some rookie errors. Here are a few common pitfalls to watch out for:

• Not starting from the correct edge: Always ensure the hook of your tape measure is properly positioned at the starting point of your measurement. Some tape measures have a floating hook that accounts for its own thickness — ignore this, and you’ll end up with inaccurate results.
• Skipping millimeters: When measuring small dimensions, don’t overlook the millimeters on a tape measure. Ignoring these tiny increments can throw off precision, especially for projects requiring exact fits like furniture building or crafting.
• Reading the wrong side: Many tape measures show measurements in both metric and imperial units. Double-check which side of the tape you’re using to avoid mixing up centimeters, inches or millimeters.
• Bending the tape: For accurate measurements, make sure the tape remains straight and taut. A curved or slack tape can result in miscalculations, particularly on longer spans.
• Relying on memory: Don’t trust yourself to remember all your measurements perfectly. Write them down as you go to avoid errors that can add up later. 
• Failing to account for the tape case: When measuring inside spaces, like the width of a drawer or a window frame, remember to include the size of the tape measure’s case if you’re using it to butt against one side. Many tape measures have the case dimensions printed on them for this reason.
• Guessing instead of measuring: For awkward or hard-to-reach areas, it’s tempting to estimate instead of taking an actual measurement. This shortcut often leads to errors and wasted materials. 

Choosing the Right Tape Measure

All types of measuring tapes do one thing — measure. But brands come with different blade coatings and casings. Some feature both metric and imperial units. Inches on top of the blade and centimeters on the bottom. 

Which one should you pick? It depends on what units you’re comfortable to use. Some people may find it convenient to work on lengths and widths in centimeters, while you may find inches easier. 

When choosing a tool, consider where you will use it. Will you use it for simple home projects to measure furniture or an area you wish to renovate? If so, one with a plastic case can do the job. This type often has centimeters and inches readings. 

If you’re an engineer or work in construction, invest in a tape measure with a metal case or rubber body. These kinds don’t break even if they’re dropped from a height.

For professionals, look for four things when shopping for your tool.

• Larger standout: Standout is the longest and straightest reach of a tape measure before it bends or snaps. Choose one with a larger standout ideal for measuring long distances and tall objects. 
• Robust housing: Pick one with a metal or rubber case with a shock-proof feature for long-term use. 

• Protective blade coating: There are nylon, matt polyester lacquer, fiberglass and stainless steel coatings resistant to corrosion, moisture and solvents. 
• Replaceable blade: If you want to save money, buy a tape measure with a replaceable blade. If it starts to rust, you can change it. 

Learning How To Read a Tape Measure the Right Way

Reading a tape measure in centimeters or inches is easy. You don’t have to be a genius in numbers to get accurate readings. The challenging part is converting different units, such as inches and centimeters, to the same unit so you can compare sizes. 

When choosing a tape measure, consider its purpose. A plastic case tape measure is good enough if you plan to do DIY home projects. Otherwise, pick a tape measure with better features, such as corrosion-resistant blade coating for professional use. 

Original Publish Date 8/3/2023 – Updated for 12/23/2024