Feet to Angstroms (ft to Å)

1 foot equals 3,048,000,000 angstroms exactly.

1 foot = 3,048,000,000 angstroms

How to convert feet to angstroms

To convert feet to angstroms, multiply the number of feet by 3,048,000,000. This factor is exact. To go the other way, multiply angstroms by 3.280839895×10⁻¹⁰ (rounded).

angstroms = feet × 3,048,000,000

Example: 10 feet = 30,480,000,000 angstroms.

About these units

Foot (ft)

US & ImperialCurrent unit

12 inches. Defined as exactly 0.3048 meters. Still the standard unit for height, altitude in aviation and room dimensions in the US and UK.

Human anatomy supplied the idea: an adult foot is roughly 15 percent of body height. Ancient cultures turned that into standards, but not the same one. The Greek pous was about 302 mm, the standard Roman pes about 295.7 mm, and a Harappan foot of about 335 mm has been reported from the Indus Valley. Historically, a foot fell somewhere between about 250 and 335 mm. Charlemagne tried to standardize units around 790 with little lasting success, and in 1593 English law fixed the statute mile at 5,280 feet.

The modern foot dates from the 1959 International Yard and Pound Agreement, which defined the yard as exactly 0.9144 meter and so the foot as exactly 0.3048 meter; the UK adopted it on 1 January 1964. The US survey foot, defined in 1893 as 1200/3937 meter, was deprecated on 31 December 2022. Feet remain in everyday use for height and rooms in the US, and ISO shipping containers are defined in them. Aviation altitudes use them too: flight level 330 means 33,000 feet.

1 foot = 0.3048 meters (exactly).

Sources: Wikipedia: Foot (unit); Wikipedia: Mile; 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.