Practical tools for measured work
Printable Protractor
Prepare a full-size 180° protractor and verify its printed calibration mark before use.
Calculate the layout, check the diagram, then print the result for the shop or jobsite.
How it works
A 180° protractor scaled to your chosen radius. Print at 100% scale and verify with the calibration square before marking angles.
Practical check: the 0 and 180 degree marks must lie on one straight baseline, and the 90 degree mark must be perpendicular through the center. Confirm the printed radius before transferring an angle.
Limitations
Paper movement, printer scaling, a thick pencil line and an inaccurately placed center point can exceed the angular precision of the printed marks. Use a calibrated metal or digital instrument where inspection tolerance requires it.
Related tools
Printable Ruler
Prepare a full-size metric, imperial or combination ruler and verify the printed calibration square before use.
Bolt Circle Template
Enter a bolt circle diameter and hole count to generate a full-size printable template with a calibration check.
Graph Paper
Create calibrated square or dot-grid paper, draw on it locally, and export a single-sheet PDF or SVG image.
Calibrated screen ruler
Measure screen-plane lengths after physical calibration, with millimetre or sixteenth-inch ticks and zoom/resize invalidation.