Choose a diameter that fits the job
The printable protractor generator treats diameter as a physical millimeter value, not a screen-pixel size. A small classroom semicircle can fit one landscape page, while a large workshop or floor template is tiled with user-defined overlap and alignment marks. Tick positions are calculated from each degree angle for 1°, 2°, 5°, or 10° spacing.
SVG receives explicit mm width and height. PDF uses the selected A4 or US Letter physical page size in portrait or landscape. The 100 mm calibration line is included in both formats. None of that can detect what a printer actually produced, so print at 100% or Actual Size and verify the line with a ruler.
Generate, print, and verify physical scale
- Choose a 180° semicircle for ordinary paper angle work or a 360° circle for bearings and full turns.
- Set the required diameter and tick interval; choose dual-direction labels, inner and outer labels, black-and-white, or transparent SVG background.
- Select paper and orientation. If the physical drawing exceeds the printable area, review the calculated page count and overlap.
- Download SVG for vector editing or PDF for fixed paper pages, or open the browser print view.
- In every print dialog choose 100% / Actual Size, never Fit, Shrink, or Scale to page.
- Measure the 100 mm line. If it is not 100 mm, correct printer settings and print again before cutting or aligning the tool.
Paper, printer, and cutting error
- SVG physical units describe intended size, but an editor or print driver can still rescale them.
- PDF page dimensions are A4 or US Letter in millimeters; printer margins can clip content near an edge.
- Tiled pages include overlap and crosshair alignment marks, but assembly error remains possible.
- Thin paper can flex while a dull cut edge can shift the baseline or center mark.
- A measured calibration line verifies that print, not permanent printer calibration.
Classroom, workshop, and large-template examples
- Classroom: print a 180 mm dual-scale semicircle with 1° ticks on landscape A4.
- Bearing lesson: use a 160 mm 360° scale with outer labels.
- Workshop: select black-and-white 5° ticks on heavier paper for a rough layout aid.
- Large template: choose a 600 mm diameter and assemble the automatically tiled pages using overlap and crop marks.
- Transparent SVG: place the generated scale in a design file while preserving its mm dimensions.
180° versus 360° labels
A 180° protractor aligns a straight baseline and can show two opposing label directions so either end starts at zero. A 360° design places zero at the top and continues around the full circle without duplicating a 360° tick on top of zero. Wider tick spacing produces fewer marks and more open labels for large viewing distances.
- 1° for detailed paper work.
- 2° or 5° for clearer mid-size templates.
- 10° for demonstrations and coarse layout.
- Transparent background affects SVG; ordinary PDF pages remain printable paper output.
Generated dimensions are not automatic printer calibration
The files encode physical dimensions and a check line, but browsers cannot measure the paper leaving your printer. Driver scaling, margins, paper feed, humidity, tiling alignment, and cutting can alter the result. Verify every important print and use a manufactured or calibrated instrument for safety-critical work.
This topic page can be read without an account. When guidance links to browser tools, ordinary measurement files remain local to your browser unless you choose to export them.