CelsiustoFahrenheit.pro

MM Ruler (Actual Size)

On-screen ruler150 mm
0102030405060708090100110120130140150mm
Calibration check
A credit card should measure 85.6 mm (3.37 in) wide
Pixels per inch used
96

Screens differ in pixel density, so calibrate first: hold a credit card (85.6 mm wide) to the screen and adjust the calibration % until it matches the ruler. Browser zoom must be 100%.

A millimeter ruler for measuring small things on screen — jewelry, screws, rings and printouts. Calibrate it with a credit card first.

How to use the MM Ruler (Actual Size)

  1. Set browser zoom to 100%.
  2. Calibrate using a credit card (85.6 mm wide).
  3. Place the item along the ruler and read the millimeters.

How it works

Each small mark is 1 millimeter, medium marks are every 5 mm and long marks with labels are every 10 mm. Because screen pixel densities differ, calibrate by matching the width of a credit card (85.6 mm) — after that, the ruler is accurate to about a millimeter. Ten millimeters make a centimeter, and 25.4 mm make an inch.

Millimeters to inches

mmInches
10.039
20.079
30.118
50.197
60.236
80.315
100.394
120.472
150.591
200.787
25.41

Frequently asked questions

How big is 1 mm?

About the thickness of a credit card (0.76 mm) or a dime (1.35 mm) — roughly 1/25 inch.

How many mm in an inch?

Exactly 25.4 mm.

How do I measure ring size with a mm ruler?

Measure the inside diameter of a ring that fits and use the ring size converter.

Is 10 mm the same as 1 cm?

Yes.

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