how fast is mach 10.4

Mach 10.4 is roughly ten times the speed of sound, which works out to about 7,700–7,800 miles per hour (around 12,400–12,600 km/h), depending on the exact conditions like altitude and air temperature.

What Mach 10.4 Means

• Mach is a ratio: Mach 1 = speed of sound, Mach 10.4 = 10.4 times the speed of sound.

• At standard conditions near sea level, Mach 1 is about 761 mph (1,225 km/h), so Mach 10.4 scales to around 7,700+ mph (12,400+ km/h).

Approximate Speeds in Common Units

• About 7,700–7,800 mph (miles per hour).

• About 12,400–12,600 km/h (kilometers per hour), using the same Mach conversion.
• At these speeds, you could circle the Earth in just over 3 hours if you could maintain Mach 10.4 the whole way (purely theoretical for now).

Why the Exact Number Varies

• The speed of sound changes with:
  • Altitude
  • Air temperature
  • Air density
• Because Mach is a ratio to the local speed of sound, Mach 10.4 at high altitude might be closer to ~6,000–7,000 mph, while near sea level it is usually quoted around 7,700+ mph.

Fun Context (Top Gun Style)

• In popular culture, speeds around Mach 10 are often referenced by hypersonic experimental jets, like the fictional Darkstar in Top Gun: Maverick.

• Real manned aircraft have reached up to about Mach 6.7 (the X-15 rocket plane), so Mach 10.4 is still well beyond what current piloted aircraft can do.

TL;DR: Mach 10.4 is roughly 7,700–7,800 mph (about 12,500 km/h), or a bit over ten times the speed of sound, with the exact figure changing slightly with altitude and air conditions.

Information gathered from public forums or data available on the internet and portrayed here.