Speed of light (c) to Mach (Ma) Conversion
Speed of light
The speed of light in a vacuum (c) is exactly 299,792,458 metres per second — a fundamental constant of nature and the ultimate speed limit of the universe. It is the basis of Einstein's Special Theory of Relativity, which establishes that no object with mass can reach or exceed this speed. The definition of the metre itself is anchored to c: one metre is the distance light travels in 1/299,792,458 of a second.
Mach
The Mach number represents the ratio of an object's speed to the local speed of sound. Mach 1 is approximately 343 m/s (1,235 km/h) at sea level and 20 °C, but varies with temperature and altitude. Named after Austrian physicist Ernst Mach, the Mach number is fundamental in aerodynamics: subsonic is below Mach 0.8, supersonic from Mach 1.2 to 5, and hypersonic above Mach 5.
| Speed of light (c) | Mach (Ma) |
|---|---|
| 0.1 c | 87403.048979592 Ma |
| 1 c | 874030.48979592 Ma |
| 2 c | 1748060.9795918 Ma |
| 3 c | 2622091.4693878 Ma |
| 5 c | 4370152.4489796 Ma |
| 10 c | 8740304.8979592 Ma |
| 20 c | 17480609.795918 Ma |
| 30 c | 26220914.693878 Ma |
| 50 c | 43701524.489796 Ma |
| 100 c | 87403048.979592 Ma |
| 1000 c | 874030489.79592 Ma |