Supersonic speed means traveling faster than the speed of sound. At sea level in dry air around 20°C, the speed of sound is about 343 meters per second (about 1,235 to 1,240 kilometers per hour, or roughly 767 to 770 miles per hour). Speeds labeled as supersonic are typically above Mach 1 and commonly range from about Mach 1.2 up to Mach 5, though who uses the term can vary by context. In practice, aircraft operating supersonically are flying faster than roughly 1,235 km/h (768 mph) under standard conditions, with higher Mach numbers corresponding to higher speeds until around Mach 5 for traditional jet configurations. For comparison, hypersonic speeds refer to Mach 5 and above. If you want, I can tailor the numbers to a specific altitude or temperature, since the speed of sound changes with air conditions.