Protractor guides
Everything you need to print a protractor at the correct size and read it correctly. Short, practical, and accurate.
How to print a protractor to scale
How to print a protractor to scale: set page scaling to 100 percent, turn off fit to page, then measure the calibration bar to confirm the size.
Read the guide 02How to use a protractor
How to use a protractor: centre on the vertex, baseline on one arm, read the scale that starts at zero. Get the steps, plus the errors that cost degrees.
Read the guide 03How to read a protractor: inner and outer scale
How to read a protractor: use the scale that starts at zero on your baseline arm, follow it to the other arm, and sense-check against 90. Get the rule.
Read the guide 04Protractor PDF versus a printout
A protractor PDF holds its exact size; a screenshot does not. Why the PDF format keeps the scale, and what to check before you print one to use.
Read the guideMore protractor guides
Deeper articles on measuring, naming, and transferring angles accurately.
Protractor types
Semicircle, full circle, bevel, digital and combination square, with the honest accuracy of each.
Read the guideWithout a protractor
Four fallback methods that work with a tape, a sheet of paper, or a ruler and some arithmetic.
Read the guideAngle types
Every angle name, the exact boundaries between them, and the notation that keeps drawings unambiguous.
Read the guideCommon angles
Where 15, 22.5, 30, 45, 60, 90 and 120 degrees come from, and the jobs that need each one.
Read the guideAccuracy tips
The five things that actually cost you accuracy, and the one minute check that catches them.
Read the guideDrawing angles
The reverse of measuring, done cleanly, including reflex angles and how to check your own work.
Read the guide