Convert Angstrom to Kilometer
Convert angstroms to kilometers instantly. 1 angstrom = 1e-13 kilometer — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Kilometer to Angstrom converter for the reverse conversion.
Units explained
Angstrom
An angstrom is a unit of length equal to exactly 10⁻¹⁰ meters (0.1 nm). Named after Swedish physicist Anders Jonas Ångström, it is the traditional unit for atomic and molecular dimensions in chemistry and crystallography.
Defined in 1907 as exactly 10⁻¹⁰ m. Although officially deprecated by the BIPM in favor of the nanometer in 1978, the angstrom remains in widespread use in chemistry and crystallography.
Angstroms express bond lengths (typical covalent bond is 1–2 Å), atomic radii, crystal lattice parameters, and X-ray wavelengths. Standard in chemistry textbooks and crystallographic data tables.
Named after Anders Jonas Ångström; defined at 10⁻¹⁰ m in 1907; deprecated as SI by BIPM in 1978 but retained universally in chemistry practice.
Kilometer
A kilometer is a metric unit of length equal to one thousand meters. It is the standard unit for measuring road distances, geographic distances, and other large-scale measurements in metric countries.
The kilometer was defined alongside the meter in 1795 using the standard SI prefix kilo- (from Greek chilioi, "thousand"), denoting one thousand units.
Kilometers are used worldwide (except the United States and a few others) for road signage, geographic distance, athletic events, and scientific distances at planetary scale. Speed limits in most countries are given in km/h.
Adopted 1795 in France as part of the original metric system; the kilometer became the global standard for road and geographic distance through the 19th and 20th century metric adoption.
Angstrom to Kilometer conversion formula
The relationship between angstroms and kilometers:
To convert angstroms to kilometers, multiply the value in angstroms by 1e-13. To reverse, multiply kilometers by 1e+13.
How to use this converter
Type a value into the calculator. The result in kilometers updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Kilometer to Angstrom converter for the reverse direction.
Step-by-step: convert angstroms to kilometers
- Write down the value in angstroms (Å).
- Multiply that value by the factor 1e-13.
- The product is the equivalent value in kilometers (km).
- To reverse, multiply the kilometer value by 1e+13.
Worked examples
Example 1 — Convert 1 Å to km:
1 × 1e-13 = 1e-13 km
Example 2 — Convert 100 Å to km:
100 × 1e-13 = 1e-11 km
Real-world example — Wavelength to road distance
A trillion angstroms equals one kilometer — the kind of conversion that appears in physics problems spanning the electromagnetic spectrum across many orders of magnitude.
1e+12 Å × 1e-13 = 0.1 km
Real-world example — Twelve orders of magnitude
A trillion angstroms maps to a single, recognizable distance in kilometers. This kind of conversion arises in cosmology and electromagnetic-spectrum exercises where atomic and astronomical scales sit side by side.
1e+12 Å × 1e-13 = 0.1 km
Angstrom to Kilometer conversion table
Standard reference values for converting angstroms to kilometers:
| Angstrom [Å] | Kilometer [km] |
|---|---|
| 0.01 | 1e-15 |
| 0.1 | 1e-14 |
| 1 | 1e-13 |
| 2 | 2e-13 |
| 3 | 3e-13 |
| 4 | 4e-13 |
| 5 | 5e-13 |
| 10 | 1e-12 |
| 20 | 2e-12 |
| 30 | 3e-12 |
| 40 | 4e-12 |
| 50 | 5e-12 |
| 100 | 1e-11 |
| 500 | 5e-11 |
| 1000 | 1e-10 |
Frequently asked questions
How many kilometers is 1 angstrom?
How do I convert angstroms to kilometers?
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How many kilometers is 100 angstroms?
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Imperial / US Customary (4 units)
Sources & references
Conversion factor (1 Å = 1e-13 km) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.