Convert A.u. of Length to Centimeter
Convert a.u. of length to centimeters instantly. 1 a.u. of length = 5.291772e-9 centimeter — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Centimeter to A.u. of Length converter for the reverse conversion.
Units explained
A.u. of Length
The atomic unit of length (a.u.) is equal to the Bohr radius — approximately 5.292×10⁻¹¹ m. Despite the abbreviation matching 'astronomical unit', this is a different unit used in atomic and molecular physics.
The atomic unit system was developed in the 1950s for quantum-chemistry calculations. The a.u. of length is defined as the Bohr radius (a₀), the most probable distance between the proton and electron in a hydrogen atom in its ground state.
The atomic unit of length is used throughout quantum chemistry, electronic-structure theory, and computational physics. Most quantum-mechanical equations simplify when expressed in atomic units rather than SI units.
Atomic unit system developed by Hartree in the 1920s; value fixed via CODATA 2018 determination of fundamental physical constants.
Centimeter
A centimeter is a metric unit of length equal to one hundredth of a meter (1/100 m). It is one of the most commonly used SI sub-units in daily life, especially for measuring small objects, body dimensions, paper sizes, and short distances.
The centimeter emerged from the French metric system established by the French Academy of Sciences in 1793. The metric system introduced decimal-based prefixes (milli-, centi-, deci-, deca-, hecto-, kilo-) to create proportional sub-units of the meter.
Centimeters are the standard unit for everyday measurement in nearly every country outside the United States. They are used for body height, clothing sizes, rainfall, paper formats (A4 is 21 × 29.7 cm), screen dimensions, and most consumer product specifications.
Developed in France during the late 18th century as part of the metric system designed by the French Academy of Sciences. Formally adopted in France in 1795 and ratified internationally through the Metre Convention signed in Paris in 1875.
A.u. of Length to Centimeter conversion formula
The relationship between a.u. of length and centimeters:
To convert a.u. of length to centimeters, multiply the value in a.u. of length by 5.291772e-9. To reverse, multiply centimeters by 1.889726e+8.
How to use this converter
Type a value into the calculator. The result in centimeters updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Centimeter to A.u. of Length converter for the reverse direction.
Step-by-step: convert a.u. of length to centimeters
- Write down the value in a.u. of length (a.u.).
- Multiply that value by the factor 5.291772e-9.
- The product is the equivalent value in centimeters (cm).
- To reverse, multiply the centimeter value by 1.889726e+8.
Worked examples
Example 1 — Convert 1 a.u. to cm:
1 × 5.291772e-9 = 5.291772e-9 cm
Example 2 — Convert 100 a.u. to cm:
100 × 5.291772e-9 = 5.291772e-7 cm
Real-world example — From wavelengths to millimeter-scale objects
A value of one million a.u. of length sounds vast at the atomic scale but converts to a small everyday quantity in centimeters — useful when relating optical-wavelength specifications to physical mounting hardware.
1000000 a.u. × 5.291772e-9 = 0.0052917721 cm
Real-world example — Sub-micron to millimeter
500,000 a.u. of length converts to a small everyday quantity in centimeters — useful when relating optical-wavelength specifications to physical mounting hardware.
500000 a.u. × 5.291772e-9 = 0.0026458861 cm
A.u. of Length to Centimeter conversion table
Standard reference values for converting a.u. of length to centimeters:
| A.u. of Length [a.u.] | Centimeter [cm] |
|---|---|
| 0.01 | 5.291772e-11 |
| 0.1 | 5.291772e-10 |
| 1 | 5.291772e-9 |
| 2 | 1.058354e-8 |
| 3 | 1.587532e-8 |
| 4 | 2.116709e-8 |
| 5 | 2.645886e-8 |
| 10 | 5.291772e-8 |
| 20 | 1.058354e-7 |
| 30 | 1.587532e-7 |
| 40 | 2.116709e-7 |
| 50 | 2.645886e-7 |
| 100 | 5.291772e-7 |
| 500 | 2.645886e-6 |
| 1000 | 5.291772e-6 |
Frequently asked questions
How many centimeters is 1 a.u. of length?
How do I convert a.u. of length to centimeters?
How do I convert centimeters back to a.u. of length?
How many centimeters is 100 a.u. of length?
Popular length unit conversions
Convert A.u. of Length to other length units
Show all A.u. of Length conversions
Metric / SI (4 units)
Imperial / US Customary (4 units)
Astronomical (8 units)
Sources & references
Conversion factor (1 a.u. = 5.291772e-9 cm) 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.