Online RulerPaper or screen ruler?
Choose paper if you need to carry the ruler, mark a line, or work on a surface away from your device. Choose the AR Ruler screen ruler if the object fits against the display and you want a quick reading without printing. Check the scale before relying on either one.
- The printable page has a 15 cm scale, a 6 in scale, and a 10 cm test line.
- The website and desktop extension offer a calibrated screen ruler in centimeters or fractional inches.
- The screen ruler saves card calibration locally. Its movable marker shows the distance from zero at the left end.
- Decide where the measurement will happen. Use paper for a mark on a workpiece or a reading away from the device. Use the screen for a small item you can hold steady against the display.
- For paper, choose Actual Size in the print dialog. Check the 10 cm test line on the finished sheet with a physical ruler before cutting out either scale.
- For the screen, set the browser zoom and display settings you plan to use. Follow the card calibration, then compare the displayed span with the matching card edge.
- Line up the first point with zero. Keep the ruler parallel to the span you want to measure and move the marker to the far point. If the item shifts, start the reading again.
Check the print
The metric and inch scales are sized separately in physical print units. A print setting that fits the page to the printable area can resize both. If the test line fails the check, inspect the print settings and print another sheet. Keep the zero mark and the full row of ticks when you trim the ruler. Read from the printed zero, since a cut edge can sit a little to either side of that mark.
Measure away from zero
If the object cannot start at zero, move the marker to each end and subtract the smaller reading from the larger. Pick the unit that matches the dimension you need to record. Use fractional inches if your drawing uses them. If AR Ruler detects a browser zoom or display change, the saved calibration may be out of date. Check the scale and recalibrate if needed.
Match the ruler to the job
Lay a paper ruler next to the line you want to draw and hold it down while you mark the endpoint. For a screen reading, choose a spot where the object can lie flat and where you can see both ends. If a bulky part blocks the marks or puts pressure on the glass, move the measurement to paper.
Can I measure from the trimmed end?
Start at the printed zero. The margin left by trimming is outside the measured span.
Are the printed scales the same length?
The scales represent different lengths. One inch equals 25.4 mm, so the final ticks of the 15 cm and 6 in scales fall at different points.
Does screen calibration read my card?
You match a physical edge to the display. The calibration takes no card data, uses no sensors, and uploads nothing.