Meters to Angstroms (m to Å)

1 meter equals 10,000,000,000 angstroms exactly.

1 meter = 10,000,000,000 angstroms

How to convert meters to angstroms

To convert meters to angstroms, multiply the number of meters by 10,000,000,000. This factor is exact. To go the other way, multiply angstroms by 1×10⁻¹⁰.

angstroms = meters × 10,000,000,000

Example: 10 meters = 100,000,000,000 angstroms.

About these units

Meter (m)

Metric (SI)Current unit

The SI base unit of length. Since 1983 it is defined as the distance light travels in a vacuum in 1/299,792,458 of a second.

Meter comes from the Greek metron, a measure. In 1791 the French National Assembly defined it as one ten-millionth of the distance from the equator to the North Pole along a great circle through Paris, after rejecting the length of a seconds pendulum because that length changes with local gravity. The surveyors Delambre and Méchain measured the meridian arc, and in 1799 a platinum bar known as the Mètre des Archives became the physical standard. NIST notes that this Earth-based meter turned out to be about 0.2 mm shorter than the true pole-to-equator fraction it was meant to represent.

The 1875 Treaty of the Meter created the CGPM and the BIPM to look after common standards, and in 1889 a platinum-iridium prototype bar took over; the original is still kept at the BIPM. In 1960 the meter was tied to 1,650,763.73 wavelengths of an orange-red krypton-86 line, and in 1983 to the speed of light, which made length a quantity derived from the time standard. The 2018 revision reworded that definition without changing the meter's size. NIST offers a handy yardstick for scale: a pace, meaning two steps, is roughly a meter or a yard.

The meter is the reference unit for length on this site.

Sources: BIPM: history of the metre; NIST: the meter and the SI redefinition; Wikipedia: Metre

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

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