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The Best Digital Protractor for Your Next Carpentry Project

When we’re talking about digital protractors, we’re not discussing the kind you used to use in school for geometry. A geometry protractor is used for measuring an angle drawn on a piece of paper. As such, it really isn’t limited to size or configuration. About the only limitation is it’s possible to see through the protractor to the lines on the paper.

Protractors used for carpentry work are used for measuring angles but these angles are on three dimensional objects. That limits the protractor quite a bit, as it needs to be able to fit inside or outside the angle. There is no integral means of determining the angle and in that sense, these tools are more a gauge than a measuring device.

At its simplest level, a carpenter’s protractor consists of nothing more than those two legs, with a bolt and wingnut to hold them together. To use them, the two legs are placed against the two surfaces making the angle and the wingnut tightened to lock them in place. Once removed from the location, the angle between the two legs is measured or transferred directly to the piece to be cut. The protractor can also be used to set up tools for cutting operations. Once the angle is measured, the digital protractor can be placed against the blade and table of a saw, allowing the angle to be set exactly.
 
While these digital protractors have everything simpler models do, they add a digital readout that measures and displays the angle formed by the two legs. This saves the step of measuring the angle of the protractor, while also increasing its accuracy. These digital protractors are a much more accurate means of measuring angles for carpentry, cabinetmaking, furniture making and general woodworking.
 
Digital protractors come in different lengths and generally speaking, it’s easier to get an accurate measurement when using a longer one. However, long protractors can be limited by the spaces they will fit in. For some types of work, especially furniture making, shorter legs on the protractor might be advantageous.
 
Besides size, the other major consideration when looking at a digital protractor is accuracy. While most units are more or less the same on this, low cost units might not be as accurate. Some low cost units have plastic legs, rather than metal ones, which could become more and more inaccurate over time. Check out our list of the best digital protactors in 2021.

What are the best digital protractors of 2021?

Starrett EC799A-8/200 Electronic Digital Protractor - Best Digital Protractor Overall

I’ve picked this Starrett protractor as my number one pick because of their reputation for having provided machinists with high quality measurement equipment for years. This protractor provides the same level of quality and accuracy to both the contractor and woodworker.

The protractor works in a number of different modes, controlled by a simple three button control, a miter mode which reads out in actual saw readings, and a single cut mode for but joints. Bubbles for both vertical and horizontal directions allow you to measure an angle off of a vertical plane and the 360 degree swing allows you to measure any and all angles.

iGaging with 7" and 4" Stainless Steel Bladed Digital Protractor - Runner Up

This is the largest digital protractor I know of, boasting a 24 inch edge on the front and 26 inch edge on the back. Both arms of the protractor are laser etched as rulers, providing both inch and metric readings while a hold function allows you to move the arms without losing your measurement. It will work for both inside and outside angles, with a measurement range of 360 degrees. Resolution and repeatability of the protractor are both 0.05 degrees, with an accuracy of plus or minus 0.2 degrees. The 24 inch protractor is a special order item, but they also have 12 inch, 8 inch and 4 inch models available.

Wixey 8"/ 200mm Angle Digital Protractor - Honorable Mention

The Wixey W418 is the longest stock protractor on the market and while not quite as long as the iGaging 24 inch unit, you don’t have to special order this one. Magnetized edges on both arms make it easier to get highly accurate readings when using the protractor for machinery or automotive uses. The protractor is limited to 180 degrees, not the 360 for the other models we’ve looked at, and it also has 0.1 degree accuracy and repeatability.

General Tools Pivoting Arm Digital Protractor - Consider

General Tools & Instruments produces a number of different digital protractors models, most of which are the standard two arm design like the others we’ve seen. I’ve picked this one because if you need to measure an angle and then cut off the end of a board to match it, the head lays alongside the edge of the board handily for transferring dimensions. The single arm is six inches long, attached to the head, which holds an oversized display. Accuracy is to 0.1 degree within its 180 degree range and the display can be inverted for use when it’s upside-down.

best 8 in. digital protractor

Wixey-WR410 8 In. Digital Protractor - Best Digital Protractor

I’ve got to give Wixey credit, they have both the largest and smallest production digital protractors on the market. This little baby has arms that are only 3 inches long, making it perfect for really tight places and it has the same magnetized arm edges and digital head their larger digital protractors do. The resolution of the display is 0.1 degrees and both accuracy and repeatability are within one digit, with a plus or minus 0.1 degree tolerance.

Buyer's Guide

In this day and age, there’s a digital version for pretty much any analog tool you can think of. Whether it’s rulers, compasses, and even barometers, digital devices are simply more accurate and reliable than their analog counterparts. The quality and convenience of digital devices have slowly driven the latter to obsolescence.

Digital protractors are one such example of tools that have become far more reliable through modern technology. Through the use of circuitry, one can easily get the precise measurement of angles without having to account for human error at all. It’s simple and easy to use, which is why it’s commonly found in many workshops and professional studios. Here’s how to find the right digital protractor for your next project.

What is a digital protractor?

A digital protractor is a special type of protractor designed to measure an angle as accurately as possible through the use of electronics. It can come in many different styles and configurations, but the main idea is the same— the device measures how much the protractor has been adjusted, and calculates the exact angle based on the adjustment.

Why do you need a digital protractor?

Unless you’re currently studying in college, there’s probably little reason why you’d need a digital protractor out of work. But here are some reasons why you’d need them if they’re relevant to your line of work:

They’re accurate

Whether you’re drawing a background for your painting or art piece or you’re measuring up dimensions for an architectural blueprint, accuracy is paramount. Even the slightest of errors can cost you precious time and resources in the future, which is why you want to make sure every single measurement you make is accurate.

With digital protractors, you don’t need to recheck your measurements or guess. The device accurately gives you the exact measurements you need, which means you don't need to waste time by measuring multiple times.

They’re reliable

No matter how professional one is, everyone is prone to human error. And in the line of work where accuracy is a must, reliability follows close behind. Even if you can be accurate with one million measurements, as long as you fail one, the entire project could fall into jeopardy. You must be sure that every single measurement is accurate, no matter how many times you measure them.

Since using our eyes can easily cause a human error, the use of digital protractors ensures that the only mistake you can make is misreading the numbers displayed on the tool. And since it’s easier to use than traditional protractors, digital protractors are far more reliable, not to mention faster to use too.

Things to consider when buying a Digital Protractor

Keep these tips in mind when getting a digital protractor.

Length

Length is an interesting metric to discuss when talking about digital protractors. You see, for some measuring tools, such as rulers, length is very important. You can only measure as long as the ruler itself. For digital protractors, however, the story is a little different.

Pretty much every single digital protractor can measure either 180 or 360 degrees. And since 360 degrees is the maximum, no matter how “long” the protractor arms are, it won’t make a difference, since the length of the arm won’t affect the range of measurement. It can, however, affect accuracy.

The shorter the length of the protractor arm, the more prone one can be to make a measurement mistake. With longer arms, you can more easily see if they line up perfectly with whatever you’re measuring. However, longer protractors can be difficult to store, transport, or work with in small spaces. At the end of the day, it all comes down to what you really need.

Range

The range of the protractor is also vital when picking one. Digital protractors can measure up to either 180 or 360 degrees. 180 degrees is a straight line, whereas 360 degrees is a circle, for those unfamiliar. You may think that the 360-degree protractor is bigger, and therefore better, but that isn’t always the case.

Say, for example, you’re measuring a set of angles, but you know that the maximum angle is only 180 degrees. In this case, having a 360-degree protractor is useless, and you may even get the wrong measurement since it can go over 180 degrees. 180-degree protractors are limited to 180 degrees, so you can measure below 180 degrees more easily than with a 360-degree digital protractor.

Battery life

Finally, there’s the battery life. Digital protractors run on electronics, and electronics don’t work without power. Digital protractors run on batteries, and thankfully most, if not all, digital protractors have replaceable batteries. Just be sure to have the proper backup batteries on hand.

Digital protractor price range

For how useful they are, digital protractors are, surprisingly, very cheap, and you can get your hands on a good digital protractor for less than $10. For more high-quality digital protractors with up to 360 degrees of measurement, you will end up spending quite a bit more, though it’s unlikely that you’ll be spending more than $40 on a single digital protractor.

How do we choose the best digital protractors?

We choose our digital protractors based on their size, shape, range, and brand history. We factor in price, customer reviews, brand reliability, and product specifications to determine if a product should be considered one of the best. Our extensive research is sure to provide you with the top products available on today’s market.

FAQ

Can I use my phone as a protractor?

There are AR (augmented reality) protractor apps available online, and they can give you an estimate of any angle it can recognize. However, the reliability and accuracy of such apps are still unclear. For now, you’re better off with a physical protractor, but if you’re in an urgent situation where a guesstimate will suffice, the phone protractor will do.

How do digital protractors work?

Essentially, the device uses a sensitive liquid that changes depending on the angle of the protractor, which sends signals that then relay the actual value through the screen, displayed in numbers.

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