Convert length and distance units — meters, feet, inches, kilometers, miles, light years and more.
| Unit | Name | Value |
|---|---|---|
| 0.001 cm | 6.684e-17 au | |
| 0.01 cm | 6.684e-16 au | |
| 0.1 cm | 6.684e-15 au | |
| 1 cm | 6.684e-14 au | |
| 5 cm | 3.342e-13 au | |
| 10 cm | 6.684e-13 au | |
| 50 cm | 3.342e-12 au | |
| 100 cm | 6.684e-12 au | |
| 1000 cm | 6.684e-11 au |
Multiply the number of Centimeters by 6.6845×10-14 to get Astronomical Units. Formula: au = cm × 6.6845×10-14. Example: 10 cm × 6.6845×10-14 = 6.6845×10-13 au. To reverse, divide Astronomical Units by 6.6845×10-14 to get Centimeters.
| Centimeter (cm) | Astronomical Unit (au) |
|---|---|
| 0.001 cm | 6.6845×10-17 au |
| 0.01 cm | 6.6845×10-16 au |
| 0.1 cm | 6.6845×10-15 au |
| 0.5 cm | 3.3422×10-14 au |
| 1 cm | 6.6845×10-14 au |
| 2 cm | 1.3369×10-13 au |
| 5 cm | 3.3422×10-13 au |
| 10 cm | 6.6845×10-13 au |
| 20 cm | 1.3369×10-12 au |
| 50 cm | 3.3422×10-12 au |
| 100 cm | 6.6845×10-12 au |
| 250 cm | 1.6711×10-11 au |
| 500 cm | 3.3422×10-11 au |
| 1000 cm | 6.6845×10-11 au |
| 10000 cm | 6.6845×10-10 au |
To convert Centimeter to Astronomical Unit, multiply by 6.6845×10-14. Example: 10 cm = 6.6845×10-13 au
To convert Astronomical Unit back to Centimeter, divide by 6.6845×10-14 (multiply by 1.496×1013). Use the swap button above.
Start with 100 Centimeters = 6.6845×10-12 au as your reference point. Scale up or down from there.
The inverse-square law of solar irradiance uses AU for distance in planetary science, but instrument apertures, detector sizes, and mirror dimensions use centimeters — conversion needed in solar telescope design and calibration.
The CGS (centimeter-gram-second) system is standard in many astrophysics papers. When converting results to AU for comparison with planetary distances or mission parameters, cm-to-AU conversion is embedded in the calculation.
Radar measurements of near-Earth objects return distances in centimeters from signal travel time, which are then converted to AU for public reporting and orbital mechanics calculations by planetary defence teams.
Space telescope primary mirrors are specified in centimeters (Hubble: 240 cm diameter) while observational distances to targets use AU — engineers convert between the two when calculating angular resolution at specific distances.
1 AU = 1.496×10¹³ cm — 15 trillion centimeters. Astronomy teachers use this conversion to make the Earth-Sun distance tangible: "It would take 15 trillion centimeter rulers laid end to end to reach the Sun."
Atmospheric scientists specify instrument dimensions in centimeters while modelling solar radiation at specific AU distances from the Sun — the cm-to-AU conversion bridges instrument design and orbital physics.
The Centimeter is a unit of Length measurement (symbol: cm). 1 cm = 6.6845×10-14 au. Used in scientific and practical Length measurement applications.
The Astronomical Unit is a unit of Length measurement (symbol: au). It is part of an internationally recognised measurement system used alongside the Centimeter.
The centimetre was introduced in 1795 as part of the French metric system — one-hundredth of a metre, from the Latin 'centum' (hundred). The CGS (centimetre-gram-second) system, built around the centimetre, became the dominant scientific measurement system in the 19th century and remains standard in astrophysics and electromagnetism today. The centimetre is now the primary unit for human body measurements, clothing sizes, and everyday objects in most of the world.
The astronomical unit has ancient roots — Aristarchus of Samos attempted to measure the Earth-Sun distance around 270 BC, estimating it at 18–20 lunar distances (the true value is about 390). For centuries the AU was estimated using Venus transit observations and trigonometry. Edmond Halley organised the first coordinated international transit-of-Venus expedition in 1716. The modern value was determined by radar ranging to Venus in 1961. The IAU formally defined the AU as exactly 149,597,870,700 metres in 2012 — a fixed constant of physics, not a measured distance.
Common use: Centimeter to Astronomical Unit conversion is needed when working with international standards, scientific publications, or reference materials that use different unit systems for Length measurement.