Inch Ruler with tape-measure fractions to 1/16

Not calibrated yet. Screens differ, so calibrate once for true actual size, it takes about 30 seconds with any bank card.
screen: 96.0 PPI
Between markers–
In inches–
Tape fraction–
Pixels–
Ruler length–
Hold an object against the screen inside the box, drag the box to move it, drag the dot to resize.
240 × 120 px

Any standard bank, credit, debit, or ID card works: the ISO/IEC 7810 ID-1 format is exactly 85.60 mm wide everywhere in the world. Hold the card flat against the screen, match the width, then apply.

True actual size after calibration Inch fractions to 1/16, like a tape measure Corner ruler & measure box Free, private, works offline
The fraction ladder

An inch ruler that speaks tape measure

This page loads the ruler in inch mode with the full imperial tick ladder: numbered inches, then progressively shorter ticks for halves, quarters, eighths, and sixteenths, exactly as a tape measure grades them. Drag the markers and the readout does the part people actually find hard: it rounds the span to the nearest sixteenth and reduces the fraction, so you read 2 3/4 in, never 2 12/16. Decimal inches, centimetres, and pixels ride alongside for whenever the plan and the shop disagree about units.

Reading the scale

How to read inch fractions on a ruler

The tick lengths are the key: the longest tick is the inch, the next longest the half, then quarters, eighths, and the shortest ticks are sixteenths. To read a mark, find the longest tick at or before it and count the smallest divisions past it: two short ticks past the half-inch mark is 1/2 plus 2/16, which is 5/8. With the ladder in your eye, the counting disappears and the readout below the ruler confirms what you saw.

The remaining rungs of the ladder, exact via 1 in = 25.4 mm; the homepage carries the halves and quarters.
FractionDecimalMillimetres
3/16 in0.18754.7625 mm
5/16 in0.31257.9375 mm
3/8 in0.3759.525 mm
7/16 in0.437511.1125 mm
5/8 in0.62515.875 mm
7/8 in0.87522.225 mm
FAQ

Inch ruler questions, answered

How do I read 1/16 inch marks?
The sixteenths are the shortest ticks. Find the longest tick at or before your point, then count short ticks past it: each is 1/16. The marker readout removes the counting entirely, reporting the span already rounded to the nearest sixteenth and reduced.
Where is 5/8 on a ruler?
Two sixteenths past the half-inch mark, or equivalently the fifth eighth-tick past the inch. On this ruler, drag a marker there and the readout confirms 5/8 in, which is exactly 15.875 mm.
How do decimal inches convert to fractions?
Multiply by 16 and round to get sixteenths, then reduce: 0.44 in is about 7/16, and 0.625 is exactly 5/8. The readout performs this automatically for every measurement, showing decimal and fraction side by side.
Is the inch ruler actual size?
After the 30-second calibration, yes: inches are rendered at your screen's measured pixels per inch, so the inch on screen is a true inch. Calibrate against any bank card, keep browser zoom at 100%, and recalibrate only when you change displays.