Pixels (CSS) to Micrometers (px to µm)

1 pixel (CSS) equals 264.5833333 micrometers (rounded).

1 pixel (CSS) = 264.5833333 micrometers

How to convert pixels (CSS) to micrometers

To convert pixels (CSS) to micrometers, multiply the number of pixels (CSS) by 264.5833333. The factor is rounded to 10 significant digits. To go the other way, multiply micrometers by 0.003779527559 (rounded).

micrometers = pixels (CSS) × 264.5833333

Example: 10 pixels (CSS) = 2,645.833333 micrometers.

About these units

Pixel (CSS) (px)

Typography & screenCurrent unit

The CSS reference pixel, defined as 1/96 of an inch. Physical screens vary, but browsers use this value to convert pixels to print units.

Pixel is a contraction of picture element, itself built from pix, a 1930s shortening of pictures. The idea is older than the word: Paul Nipkow's 1888 German patent spoke of a Bildpunkt, or picture point, and the phrase picture element appears in US patents filed as early as 1911. Frederic C. Billingsley of the Jet Propulsion Laboratory published pixel in 1965, writing about scanned images from space probes to the Moon and Mars, and said he had learned it from Keith E. McFarland, who reported it was already in use around 1963.

A pixel in a photograph is a sample, not a fixed length, and screens vary widely in size. CSS therefore defines px as an abstract reference pixel of exactly 1/96 inch, based on the visual angle of one pixel on a 96 dpi device held at arm's length. The CSS specification gives that angle as about 0.0213 degrees for a nominal arm's length of 28 inches, which works out to about 0.26 mm. On sharper screens a single CSS pixel spans several device pixels. Earlier CSS versions did not fix the ratio, but too much existing content assumed 96 dpi.

1 pixel (CSS) = 0.0002645833333 meters (approximately).

Sources: W3C: CSS Values and Units Module Level 3, absolute lengths; Wikipedia: Pixel

Micrometer (µm)

Metric (SI)Current unit

One millionth of a meter, also called a micron. Typical bacteria are a few micrometers long; a human hair is roughly 70 µm thick.

Two names, micron and micrometer, have shared this unit for more than a century. The prefix micro- was adopted in 1873 alongside the CGS system, and in 1879 the term micron and the symbol μ were officially accepted for the micrometer when used on its own. That created a clash once SI came along: μ was also the symbol for the prefix micro-. The 13th CGPM revoked micron and its symbol in 1967 to 1968, leaving micrometer and μm as the official name and symbol, though micron lives on in everyday speech.

A micrometer is a thousandth of a millimeter, and it is the natural scale for biology and filtration. A typical red blood cell is 6 to 8 μm across, a bacterium is 1 to 10 μm long, and a fog droplet is around 10 μm. Human hair ranges from about 17 to 181 μm in diameter, and paper is 70 to 180 μm thick. Infrared radiation is measured in micrometers of wavelength, and wool is graded by fibre width. Some American writers keep micron because micrometer also names the caliper-style measuring tool.

1 micrometer = 0.000001 meters (exactly).

Sources: Wikipedia: Micrometre; Wikipedia: Metric prefix

Related conversions

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