Online Ruler
Online Ruler

Ruler on Full Screen

Choose a screen edge or place an object to measure.

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Imperial Standard: 1 inch = 25.4 mm

Online Ruler in Inches (1:1 Actual Size)

Measure in imperial inches with precise fractional subdivisions (1/2", 1/4", 1/8", and 1/16") calibrated to your screen’s physical dimensions.

Understanding Fractional Inch Divisions

The imperial inch is subdivided into fractional binary increments rather than decimals. Our ruler clearly demarcates:

Half-inch (1/2"), quarter-inch (1/4"), eighth-inch (1/8"), and sixteenth-inch (1/16") marks with tiered line heights for effortless reading.

Quick Imperial to Metric Conversions

1/16 inch

≈ 1.5875 mm

1/8 inch

≈ 3.175 mm

1/4 inch

≈ 6.35 mm

1/2 inch

≈ 12.70 mm

1 inch

= exactly 25.40 mm

12 inches (1 foot)

= exactly 30.48 cm

Perfect Calibration for Imperial Scale

Calibrate with your display diagonal or payment card to ensure 1 inch on screen is exactly 25.4 millimeters.

Calibrate Inch Scale