Printable protractor generator
Set the size, the degree marks, and 180 or 360 degrees. Download a print-accurate PDF or SVG with a calibration bar, then print at 100 percent and confirm the scale. It all runs in your browser.
Live preview
The PDF is exact only when you print at 100 percent. Set page scaling to None or Actual size, never fit to page, then measure the calibration bar to confirm.
Print it to scale in four steps
- Set the size and marks. Choose a half or full circle, type the diameter you need, and pick how often the degree marks appear.
- Download the PDF. The file is built on your device with real physical dimensions, so nothing is sent anywhere.
- Print at 100 percent. In the print dialog, set page scaling to None or Actual size. Turn off fit to page or shrink to fit, which silently change the size.
- Verify the calibration bar. Lay a ruler across the printed 100 millimetre bar. If it reads 100 mm, your protractor is exact. If not, reprint at actual size.
Authoritative printable-tool guides agree on the rule: print at actual size with scaling turned off, then verify against a known length. As one guide puts it, avoid "fit to page", "scale to fit", or "fill entire paper", because they print the image larger or smaller than its actual size.
Source: Printable-Ruler.net, printing instructions: https://www.printable-ruler.net/How the scale stays exact
A PDF page is measured in points, where one point is one seventy-second of an inch, so one millimetre is 2.8346 points. The protractor is drawn directly in those physical units rather than in screen pixels, which have no fixed real-world size. That is why a 150 millimetre protractor is laid down at exactly 150 millimetres, and why the only thing that can change it is the print scale.
The on-screen preview is generated from the same geometry as the PDF, so what you see is what prints. The calibration bar exists because no tool can control your printer for you: measuring it is the two-second check that proves the scale survived the trip to paper.
Frequently asked questions
How do I make sure it prints to the right size?
In the print dialog, set page scaling to None or Actual size and turn off fit to page or shrink to fit. Then measure the printed 100 millimetre calibration bar. If it reads 100 mm, every angle and dimension on the sheet is exact.
What size protractor should I pick?
A standard school protractor is a 180 degree semicircle about 150 mm across, which is the default here. A 100 mm version is handy for small work, and a full 360 degree circle suits bearings and full-turn angles. You can also enter any custom diameter that fits the page.
Which paper sizes are supported?
US Letter and A4. The tool caps the diameter to whatever fits the chosen page with a safe margin, so the protractor never runs off the printable area. A single page holds a protractor up to roughly 190 mm across.
Can I save an SVG instead of a PDF?
Yes. The SVG export carries real millimetre dimensions too, so it also prints to scale at 100 percent and can be opened in design or cutting software.
Is the angle math accurate?
Each degree is one 360th of a full turn, placed with exact trigonometry. The 0 mark sits on the baseline, 90 points straight up on a 180 degree protractor, and the ticks fall at precise one-degree intervals around the arc.