Inches to Angstroms (in to Å)

1 inch equals 254,000,000 angstroms exactly.

1 inch = 254,000,000 angstroms

How to convert inches to angstroms

To convert inches to angstroms, multiply the number of inches by 254,000,000. This factor is exact. To go the other way, multiply angstroms by 3.937007874×10⁻⁹ (rounded).

angstroms = inches × 254,000,000

Example: 10 inches = 2,540,000,000 angstroms.

About these units

Inch (in)

US & ImperialCurrent unit

1/12 of a foot. Defined as exactly 25.4 millimeters since 1959, when the US and Commonwealth countries agreed a common international inch.

Latin uncia, meaning one-twelfth, is the root of both inch and ounce, and it passed into Old English as ynce. Roman measurers divided their foot into twelve unciae, and the English inch kept that twelfth. After 1066 an inch was reckoned as three barleycorns, and a 1324 statute attributed to Edward II spelled out the definition as three grains of barley, dry and round, placed end to end lengthwise. For centuries the inch was simply a twelfth of a foot, or a thirty-sixth of a yard, and the US and UK each kept their own copy of the standard yard.

Those copies differed slightly until the 1959 international agreement fixed the yard at exactly 0.9144 meter, which made the inch exactly 25.4 millimeters. The US adopted it in 1959 and the UK ratified it in 1963, effective 1964. Today the inch is still the customary unit in the United States and Canada, and the UK keeps it on road signs. Worldwide it also names display diagonals, wheel rims, tire codes and pipe sizes.

1 inch = 0.0254 meters (exactly).

Sources: Wikipedia: Inch; Wikipedia: Yard; NIST Guide to the SI, Appendix B.8: conversion factors

Angstrom (Å)

ScientificTraditional unit (still used in some regions)

One ten-billionth of a meter (0.1 nm). Named after Anders Ångström and used for atomic and molecular sizes and bond lengths.

Swedish physicist Anders Jonas Angstrom (1814-1874) charted the solar spectrum in 1868 in multiples of one ten-millionth of a millimeter, and solar physicists later named that interval after him. It equals 10 to the minus 10 meter, 0.1 nanometer or 100 picometers. Atoms and bonds fit it well: hydrogen is about 0.5 angstrom in covalent radius, and visible light spans roughly 4000 to 7000 angstroms.

The unit's size was not always exact. In 1907 the International Angstrom was fixed as 1/6438.4696 of the cadmium red line wavelength, a definition the 7th CGPM endorsed in 1927. The 1960 redefinition of the meter by a spectral line made it exactly 10 to the minus 10 meter, and NIST lists the conversion as exact. A later X-ray version, the angstrom star of 1965, was obsolete within about ten years. The unit was listed as acceptable by NIST and BIPM until 2019 but is absent from the 9th SI Brochure, and nanometers and picometers are slowly replacing it.

1 angstrom = 1×10⁻¹⁰ meters (exactly).

Sources: Wikipedia: Angstrom; NIST Guide to the SI, Appendix B.8; Wikipedia: Picometre

Related conversions

See all length units.