Convert Centimeter (cm) to Astronomical Unit (AU) instantly.
About these units
Centimeter (cm)
The centimeter, 1/100 of a meter, strikes a balance between precision and ease of communication, making it indispensable in everyday life. Its size is well-matched to human-scale objects—furniture, body dimensions, school supplies, and clothing—so people in metric countries regularly estimate or visualize lengths in centimeters without tools. Many professions rely heavily on centimeters, including medicine (wound sizes, tumor dimensions), tailoring, building trades, and interior design. In science, centimeters serve as a practical unit for measurements too small for meters but too large for millimeters. Biologists, for example, may measure specimen sizes or growth stages in centimeters. Its intuitive scale and decimal alignment with meters ensure that both laypeople and professionals can convert easily among related units.
Astronomical Unit (AU)
The astronomical unit (AU) is one of the most important distance units in astronomy and planetary science. Defined as exactly 149,597,870,700 meters, it represents the average distance between Earth and the Sun. Early astronomers could estimate the AU only indirectly through geometric and observational methods; modern techniques such as radar ranging and spacecraft telemetry have vastly improved its precision. The AU serves as a natural and intuitive scale for describing distances within the solar system. Planetary orbits, asteroid trajectories, comet paths, and interplanetary mission distances are often expressed in astronomical units because they avoid cumbersome scientific notation. For instance, Jupiter orbits at about 5.2 AU from the Sun, while the asteroid belt lies roughly between 2 and 3.3 AU. Beyond practical measurement, the AU forms part of a conceptual framework for understanding solar system layout. It appears in discussions of habitable zones, solar radiation intensity, and celestial mechanics. The unit's significance extends from education to high-level astrophysics, making it one of astronomy's cornerstone measurements.