GemRed 82305 Digital Angle Finder Review

Two different tools get called an angle finder and buying the wrong one is the most common mistake here.

A digital protractor — this tool — has two blades on a hinge and measures the angle between them. It reads angles that exist: the corner of a room, the splay of a chair leg, the mitre needed where two out-of-square walls meet.

A digital angle gauge is a small box with a magnet and an inclinometer. It measures tilt relative to a reference surface, which is what you want for setting a saw blade to 45 degrees.

They are not interchangeable. This page is about the first kind.

Why it beats a sliding bevel

A sliding bevel copies an angle without telling you what it is. That is fine when you can carry the bevel to the saw and set the blade against it. It is useless when you need to halve the angle for a mitre, or when the angle has to be cut on a mitre saw with a numeric scale.

The GemRed gives you the number. Sit the blades in the corner, read 87.4 degrees, and you know each mitre is 43.7 — arithmetic a bevel gauge cannot do for you.

The blades lock, so once you have the reading you can also use it as a physical template against the workpiece.

The accuracy conversation

The display shows tenths of a degree. The real-world accuracy of any hand-held protractor is determined by how flat and clean the surfaces you are registering against are. On a planed edge, the reading is good. On a plastered wall corner with a lump of filler in it, the tool is precise and the measurement is not.

Measure in two or three places along a corner and use judgement.

Care

The hinge is the wear point. Do not drop it, do not use the blades as a pry bar, and check periodically by closing it fully and confirming it reads zero. If it does not, most of these have a zero button that will recalibrate it.