Convert Miles per Hour to Mach 20
Convert Miles per Hour (mph) to Mach 20 (Ma20) instantly and accurately.
Conversion Formula
Ma20 = mph × 6.568515090e-5
About Miles per Hour
A mile per hour (mph) = exactly 0.44704 m/s - the primary road speed unit in the US, UK, and a few other countries. US interstate limits 65-85 mph; UK motorway 70 mph. Walking ~3-4 mph; club cycling 20-25 mph. MLB elite fastball 100 mph (44.7 m/s). Saffir-Simpson Category 5 hurricane ≥157 mph. Boeing 737 MAX cruises at ~521 mph (Mach 0.79). 1 mph = 0.44704 m/s = 1.60934 km/h = 0.86898 kn.
About Mach 20
Mach 20 ≈ 6,805.8 m/s (24,501 km/h) at ISA sea level - the peak heating regime of ballistic re-entry. Shock layer temperature exceeds 10,000 K; plasma sheath causes radio blackout. Space Shuttle decelerated through Mach 20 at ~75-80 km altitude; Apollo CM hit the atmosphere at ~Mach 36; ICBM warheads re-enter at Mach 18-24. DARPA HTV-2 reached Mach 20 in 2011. 1 Mach 20 = 6,805.8 m/s.
Quick Reference Table
| Miles per Hour (mph) | Mach 20 (Ma20) |
|---|---|
| 1 mph | 6.569 × 10-5 Ma20 |
| 2 mph | 0.00013137 Ma20 |
| 5 mph | 0.000328426 Ma20 |
| 10 mph | 0.000656852 Ma20 |
| 25 mph | 0.00164213 Ma20 |
| 50 mph | 0.00328426 Ma20 |
| 100 mph | 0.00656852 Ma20 |