Learn how to read a tape measure accurately and discover all the hidden clever features like the movable tab, black diamond, and more!
If there is one crucial part of making anything – its the tape measure! It is extremely important to get the measurements right and accurate.
It might seem like a no-brainer but all those marks, symbols and fractions can make your head spin when you try to use a tape measure in a pinch.
Ask me. I grew up in the metric system. Any measurement under a 1/4″ has me cross-eyed and counting lines. I try my best to avoid smaller measurements whenever I design a project!
But living in this country for the last 18 years, and building furniture for the last 7 of those years has made me more comfortable with using the imperial system.
PLUS, ever since I discovered all the clever features in measuring tapes, I have a new appreciation for it!
RELATED: Check out my starting guide for woodworking
Let’s break down everything about the tape measure!
Table of contents
Anatomy of a tape measure
Let’s talk about the parts of a tape measure.
The tape
The tape is basically a flexible ruler – made with fiberglass or metal. Measuring tapes can also be made of cloth but the ones commonly using in woodworking and DIY are not. It is expandable and retractable inside the case.
Tape measures come in both Imperial Units (inches and feet) and metric (centimeters and meters) and have unit breakdowns for further accuracy.
Specialized versions for home improvement and woodworking are usually yellow and have special markings for stud intervals and truss locations. (more on this below)
The case
The case is the housing for the measuring tape. It is made of plastic or metal. It can come in various sizes depending on the length of tape it needs to house.
The metal tab
At the front of the tape is a metal tab that has a little movement built-in.
This tab not only makes it easier to get accurate measurements with the tape, it has a few other hidden features.
We will discuss that in detail below.
The thumb lock
The thumb lock helps hold and lock the tape in the extended state to help with measurements. Once measurement is completed, you can release it to retract the tape.
The belt clip
The belt clip on the back of the case which can help you keep your tape measure close!
How to read a tape measure in inches
Reading an Imperial unit tape measure is all about dividing up the markings.
- Start by looking at the whole inch markings. These are the longest lines on the tape measure and typically have large numbers to the left of them. As the fraction decreases, so do the length of the marks.
- The next largest mark halfway between the numbers is the 1/2″ mark.
- The next largest mark halfway between the 1/2″ marks are the 1/4″ marks.
- The marking halfway between 1/4″ marks is 1/8″.
- The marking halfway between 1/8″ is 1/16″. The marking halfway between the 1/16″ is 1/32″.
- Once you have identified the line where you want to measure or mark, simply count the fraction to that line.
- That is your measurement.
Most tapes go down to 1/16″ and some will go down to 1/32″. The tape in the picture goes down to 1/16″.
It takes some practice to quickly read the markings and figure out the fractions but with time, it definitely gets better.
How to get accurate readings with a tape measure
Getting accurate measurements doesn’t only involve reading the lines on the tape.
You should protect your tape measure like your child. Don’t let the tape twist or bend. This can damage the tape and lead to inaccurate readings.
Here are a few little details to pay close attention so you get the most accurate readings –
- Keep the tape straight – When measuring, keep the tape completely straight – in all directions.
- Any sagging will make the measurements inaccurate.
- If the tape is at an angle, the measurement will be inaccurate.
- Burn an inch – If your tape measure is old and you aren’t confident about its accuracy, start measuring at 1″. Then simply subtract 1″ for the final measurement. This only works in case of smaller objects where y our arms can span the length to hold the tape in place.
Tape Measure safety
Yes, you read that right! There are safety measures to follow while using the seemingly harmless tape measure.
Very important – don’t let the tape reel back into the housing at warp speed.
The metal tape can be extremely sharp (think paper cut but with metal!). It can cause bruises if left to recoil uncontrollably. It can also flail around hitting others or surroundings.
Safely recoil the tape measure by gently hold the tape near the mouth of the case and use fingers to control the speed at which the tape goes back in.
Clever Tape Measure Features you should know
Do you know the little unassuming tape measure has plenty of hidden features to make life easier and make reading them more accurate.
1. Why is the tape measure end loose?
I can’t tell you how many times I have heard – “Is my tape measure broken? Why is this silver tab moving so much?”
No. The tape measure is NOT broken. That silver tab is meant to move.
In fact, it’s motion is what helps you get accurate readings. I think this is one of the most important and genius features on the tape measure.
Let’s dive deeper into it.
The distance the tab moves is the equal to the thickness of the tab.
When you are pulling to measure, the tab extends out so the zero starts on the inside edge of the tab.
When you push to measure – like inside a box, zero starts at the outside edge of the tab.
It is a simple feature but makes a HUGE difference in the accuracy of the tape.
2. Why is there a hole in the tab?
The hole in the tab can help with 2 things –
- Hook it – if you are measuring from the middle of a surface and your arms are not long enough to reach the other end, simply add a nail or thin screws to hook the tab and measure.
- With the tab hooked on the nail/screw, you can hold the pencil to the desired reading to draw a circle at any size.
3. What’s the number of the case?
I am glad you asked! It is an important feature that helps make life easier for you.
The number denotes the length of the case itself.
If you have to measure inside a box or window frame, you can simply rest the entire tape measure inside and get your measurements. Simply add the reading on the tape measure and the number of the case.
For example, my tape measure is 3-3/8″ wide. The above measurement will be 30-1/2″ + 3-3/8″ = 33-7/8″.
4. What is the black diamond on the tape measure?
The black diamond is the truss spacing.
Each black diamond is 19.2″ apart and appear at those multiple until 96″ or 8′.
Not just the black diamond, the typical stud spacing is 16″ and you will find many measuring tapes that mark the 16″ increments with red boxes.
Apart from that, every tape has the total length of the tape written at the very beginning.
5. Marking tool in a pinch
Raise your hand if you have ever lost a pencil in the workshop.
In a pinch, the sharp ends of the tab can also act as a temporary marking tool by scraping a mark in the wood-like-medium.
My Favorite Tape Measure
If you are still getting used to quickly reading the lines and fractions, the alternative is a tape measure that has the fractions already marked!
What’s even better is to have the decimal equivalents of each fraction marked on the tape measure.
This tape measure has everything. Now, it might not be as heavy-duty as some others below, but it is definitely life-changing.
What do you think?
Was this article helpful? Aren’t these little hidden features super-clever?!
Nanda says
Excellent information and impressive pictures, I thought my tape has defective tab. This information made me clear off so many doubts and also new information. I’m kind of still adjusting to imperial units kind of confusing.
Linda Weeks says
Well I, for one, learned a lot from this post; for instance I didn’t realize that ‘our’ system of measurement is called ‘imperial’ as opposed to metric! I grew up learning the ‘imperial’ way of measuring, and everybody else groaned when the teacher told us to learn the metric system, since it was far more precise! But wouldn’t you know it, I was too stubborn to try. And I’m too old now. Ha! I appreciate this post considerably, and will do my best to commit it to memory!
Dale L Charpentier says
Excellent, simple & very useful explanation. I knew some of the tape features, but she brought out some I hadn’t paid attention to. Thanks for the tips.
Oven Fresh Cake says
Amazing work!! Looking for more from you.