How to Use a Tape Measure (With Pictures)

5 tape measures

You’ve probably heard the famous saying “measure twice, cut once.” That’s great advice, but it does require you to know how to use a tape measure correctly. While there are other measuring devices out there, the most common one you will find in toolboxes is the tape measure. It may seem simple, but there are quite a few tricks built into your tape measure. Here’s an essential educational guide on how to use one.

The parts of the tape measure

A tape measure is made up of four parts: a tang, a blade, a lock and a casing. Credit: Nathan Hamilton

Tape measures come in various shapes, sizes and colors, but these hand tools all have the same basic parts.


The casing is the outside shell of the tape measure. It can be plastic, metal or rubber, or even a combination of materials. Look for a tape measure that is sturdy and can take a few knocks. The best tape measures often have study clips so you can hook them on your belt while you work.


The blade is the actual metal “tape” that has the measurements on it. Take care not to bend it, because that can prevent the tape measure from working properly and measuring accurately.


The tang is the metal piece that functions like a hook at the end of the tape measure. This piece is actually more important than you think — as you will see in a minute.


The lock is a button on the side of the tape measure that sets the blade in place. Some tape measures have an auto-lock feature. With an auto-lock, you push the button to retract the blade.

How to use a tape measure

You might think it’s simple to use a tape measure, but there are a few steps you should know. Here are the proper steps to using a tape measure:

  • Pull out the tape measure blade and hook the tang onto the edge of the object you want to measure.
  • Once the tang is secure, pull at the casing to expand the tape measure and stop it where the object ends or your desired measurement is reached. Set the lock and lay down the tape measure so you can free up both hands.
  • Move your hands close to the desired measurement and pull the tape measure slightly so that the floating tang is fully extended.
  • With one hand still pulling the blade taut, use that same hand to roll the edge of the blade directly onto the object so it lays flat. Then strike your measurement using a pencil with your other hand. Rolling the blade on edge ensures an accurate measurement.
  • If measuring the length of a piece, read your markings carefully and write down the measurement. Suppose you have a tape measure with 1/16″ intervals and the 3/8″ line aligns with the edge of the object perfectly. Look to the left of the 3/8 ” line and note the inch mark. If it is 5, then your length becomes 5 and 3/8 inches, or 5.375″.
  • Once your measurement is recorded or marked, unlock the blade using the tape measure button. Be sure to moderate the retraction speed. Repeatedly slamming the blade and tang into the casing can lead to malfunctions over time.

RELATED: How to Read a Tape Measure

Tape measure tangs are loose for a reason

There’s a clever feature built right into a tape measure. If you wiggle the tang, you will notice that it moves. It can slide 1/16th of an inch so that your measurement will be correct for measuring both interior and exterior dimensions.

Make sure that if you measure an inside dimension, such as measuring between two parallel walls, you press the tang against one wall. This will ensure the tang floats 1/16 of an inch inward for an accurate measure.

On the other hand, when you measure from an outside edge, put a little tension in the tape measure to slide the tang out. You’ll get consistently precise measurements by remembering to set your tang every time.

Tape measure tips and tricks

Using a nail or screw head

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Closeup picture of the small slot in a tape measure’s tang that can be hooked onto a screw or nail. Credit: Nathan Hamilton

There is a small slot in the tang’s face. It’s there for good reason. The design allows you to hook the tang onto a nail or screw if you need to measure from it. This is very helpful when one person needs to measure a large distance.

Interior measurements

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Most tape measures will include the width of the casing to assist in measuring interior dimensions. This casing is 3″ long. Credit: Nathan Hamilton

There is usually a marking on the base of each tape measure casing. This allows you to measure inside dimensions without bending the tape. Just slide the blade out and put the tang into position. Then extend the casing and butt the casing directly up to the interior edge. The length of the tape plus the marking on the base of the casing is your interior dimension.

Measuring stud and floor joist locations

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Top photo: The red-highlighted box is included at 16″ intervals to help lay out studs for walls. Bottom photo: The diamond on a tape measure is included at 19.2″ intervals to help lay out floor joist locations. Credit: Nathan Hamilton

Tape measures often have red squares every 16 inches and black diamonds every 19.2 inches. These marks are the standard spacing for studs and floor joists, respectively. The markings make it easy to work out where those framing members are behind drywall and in floors.

Round up your measurement when in doubt

If a measurement falls exactly halfway between two lines on the tape measure, use the larger dimension. It’s better to err on the side of excess. You can always nibble away with a saw or sand a little off the end to get the exact length, but you can’t add it back!

Use the tang when you don’t have a pencil handy

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Use the tangs serrations to scribe a line. Credit: Nathan Hamilton

Many tape measures feature a serrated tang. You can use the serrations as a scribing tool if you don’t have a pencil available. Just press down on the tang and give a slight back-and-forth movement.

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Nathan Hamilton
Nathan Hamilton is the founder of DIY Gear Reviews and a recognized expert in the home and DIY space. He has over 200 bylines covering topics such as power tools, hand tools, and woodworking. Nathan is the strategic director for DIY Gear Reviews, deciding everything from the content covered to designing the testing methodologies for lab-tested reviews. He can be emailed at


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