How Does a Digital Angle Finder Work?

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Digital angle finders are small, handheld tools that help woodworkers measure existing angles and/or mark up stock for angled cuts. They are essential for fine woodworking, and its important to understand the various type and how to use the tool. This article will explain further how does a digital angle finder work.

Types of Digital Angle Finders

There are two products that are sold under the name ‘digital angle finders’; box-shaped angle finders and hinged-arm angle finders. Digital angle finders of either type are usually powered by a battery.

Digital angle finder on top of table saw blade

Box-Shaped Digital Angle Finders

One type of digital angle finder is a small box and are the most common. The best angle gauges are also sometimes called angle finders and are used primarily to find the correct angle for your saw blade.

This kind of digital angle finder must be used in the upright position. You cannot lay it flat on its back.

A box-shaped digital angle finder must first be set on a flat surface such as a table saw. A button is used to zero out the display. When the angle finder is then placed on a metal surface such as a blade, small magnets on the underside of the box will keep it in place.

As you adjust the blade, a pendulum inside the box allows the angle finder to measure the blade’s angle. Digital angle finders are able to measure both positive and negative angles. When the digital readout shows the desired angle, the blade is locked in place.

Don’t forget to remove your digital angle finder from the blade before you make the cut.

Hinged-Arm Digital Angle Finders

Hinged-arm digital angle finders consist of two ruled blades, connected by a hinge. This type of digital angle finder is sometimes called a digital protractor. Inside the hinge is a digital reader.

Like a box-shaped digital angle finder, hinged-arms models must be calibrated before use.

Hinged-arm digital angle finders can be used to set a blade angle, measure an existing angle, or mark up stock for cutting. The angle finder is laid against a flat surface, and the arms are then arranged to the appropriate angle.

The digital reader measures the angle by determining how far apart the two blades are. That information is displayed on a small screen and is expressed in degrees.

Digital angle finder beside table saw

Digital Angle Finder Features

Many digital angle finders go beyond basic functions with additional features to make your life easier.

Angle Conversion

When fitting two pieces of wood together at an angle other than 90 degrees, there’s some arithmetic involved. Some digital angle finders can automatically compute the appropriate measurements for complementary angles, removing a potential source of error.


Some digital angle finders have a limited memory capacity. They can store your last measurement (or several measurements, depending on the model) for future reference. If you’re cutting out many angled pieces, such as for a parquet floor, this feature can be a lifesaver.


An inclinometer measures how much a surface slopes or pitches. A digital angle finder with a built-in inclinometer can be used to measure the pitch of your roof or determine the slope of a retaining wall.

Twist Dial

When you’re measuring an angle in one place, but working on your piece in another location, you can use the twist dial to lock the arms of a hinged-arm angle finder into position.

Bubble Level

A bubble level on the bottom arm of your digital angle finder helps you make precision measurements.

Impact Resistance

Some digital angle finders have a super-strong housing that can resist damage from drops up to 20 feet. Unless you’re a construction worker or planning to spend a lot of time on your roof, this feature probably isn’t necessary.

Dust Resistance

Chances are, you’ll be using your angle finder in the vicinity of your table saw, and there’s likely to be a lot of dust swirling around. When this dust settles on a digital angle finder, it can find its way into the inner workings, clog the buttons, and eventually make the tool unusable. Dust resistant measures help slow this process down.

How to Use a Hinged-Arm Digital Angle Finder

A digital angle finder with two arms is helpful for determining the angle at which two surface meet.

  1. Choose where to measure. Check for obstructions, high spots, or debris that could interfere with the digital angle finder. Both surfaces should be clean, clear, and flat.
  2. Calibrate the angle finder. If you’re using a digital angle finder, close the arms so that the finder is measuring zero degrees. Press the taro or zero button on your angle finder to calibrate it.
  3. Unlock the hinge. The hinge may have a locking or tightening mechanism. Loosen it so that the arms of the angle finger move freely.
  4. Set the hinge and arms. Push the hinge into the corner of the angle you are measuring. Open the arms so that they lay flat and flush against the two surfaces.
  5. Lock the hinge. Relocking the hinge prevents you from accidentally losing your angle.
  6. Find the angle. Press the button on your digital angle finder that displays the angle of the arms.

How to Use a Box-Shaped Digital Angle Finder

A box-shaped digital angle finder is used to find the correct angle for your saw blade.

  1. Set the blade to zero degrees. To start this process, your saw blade must be in a neutral position.
  2. Place the angle finder on the blade. Box-shaped angle finders have a few small magnets in the base, allowing them to cling to your saw blade. 
  3. Calibrate the angle finder. Zero out the display by pressing the taro or zero button.
  4. Tilt the blade. Use your saw’s tilting mechanism to change the angle of the blade.
  5. Watch the display. As you tilt the blade, the digital readout will display the measurement of your angle. Stop when you reach the desired incline or decline.
  6. Remove the angle finder from the blade before you start cutting.


Digital angle finders use a battery, sensors, and a digital readout to display the measurement of an angle. Some digital angle finders measure distance and automatically calculates the angle based on that measurement while others rely on a pendulum to measure the angle directly. There are a number of additional features that can be included with a digital angle finder.

Ellenkate grew up on job sites run by her family’s construction company. She earned her theater degree from The Hartt School, a prestigious performing arts conservatory in Connecticut. Her design and DIY work from her Chicago loft was featured in the Chicago Reader and on Apartment Therapy.