Ruler in Inches

This ruler in inches lays an inch scale along the edge of your screen, complete with 1/16-inch marks. It is the same online ruler trusted for measuring screen elements, printed layouts, and any object you place against the display — just switch the unit to inches.

How to use the ruler in inches

Select in as the unit in the toolbar and the ruler in inches appears on the chosen screen edges, starting at the top-left corner. Whole-inch numbers are labeled, half-inch marks are longer, and the smallest ticks show sixteenths of an inch. Press M to enter measure mode and the ruler in inches can verify the distance between any two points.

Calibration for an accurate ruler in inches

An uncalibrated screen assumes a default PPI, which makes any ruler in inches drift on non-standard displays. Run Smart Auto-Detect for known devices, enter your monitor diagonal for a quick fix, or use credit card calibration for the most accurate ruler in inches. Your calibration is stored locally and reused on every visit.

Inches to centimeters quick chart

The ruler in inches doubles as a converter: switch units with the U key and the same measurement is redrawn in centimeters. Use the chart below to sanity-check the ruler in inches against known object sizes.

Inch conversion reference
InchesCentimetersMillimeters
1 in2.54 cm25.4 mm
3 in7.62 cm76.2 mm
6 in15.24 cm152.4 mm
8.56 in (credit card)21.74 cm217.4 mm
12 in30.48 cm304.8 mm

FAQ

How do I get a true ruler in inches on my screen?
Calibrate first — the credit card method makes this ruler in inches accurate to roughly 0.5mm, because the card is exactly 3.37 inches wide.
Does the ruler in inches show fractions?
The scale marks every 1/16 inch. The ruler in inches labels whole inches, and the measure readout shows decimals like 4.75 in.
Can I switch the ruler in inches to centimeters?
Yes, press U or tap the unit buttons — the same online ruler redraws instantly in cm, mm, or pixels.

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