Convert Mach to Meters per Second

The Mach (symbol: Ma) is a unit of speed. A dimensionless speed ratio M = v/a, where v is the object speed and a is the local speed of sound in the surrounding medium. Named after Austrian physicist Ernst Mach (1838-1916) whose 1887 shadowgraph photographs first visualized supersonic shock waves. Mach 1 is the speed of sound (sea-level standard atmosphere ISA = 340.3 m/s = 1,116 ft/s = 661 kn; varies with √T_absolute — at 11 km altitude ISA T = -56.5 °C giving a = 295.1 m/s = 573.6 kn). Flight regimes per NASA/FAA convention: subsonic M < 0.8 (commercial jetliners cruise M 0.78-0.85 — Boeing 787 M_MO 0.90, Airbus A350 M_MO 0.89); transonic M 0.8-1.2 (shock formation, area-rule design per Whitcomb 1952); supersonic M 1-5 (Concorde was M 2.04 cruise; SR-71 Blackbird M 3.2+; F-22 Raptor M 2.25 + supercruise M 1.82); hypersonic M 5-10 (X-15 record M 6.72 Pete Knight 1967; SR-72 design goal M 6); high-hypersonic M >10 (Boeing X-51 Waverider M 5.1 sustained; HTV-2 hypersonic glide-vehicle test M 20); re-entry M 20-25 (Space Shuttle peak entry M 25; Apollo command module M 36 lunar-return). Because the speed of sound varies with temperature (a = √(γ·R·T)), pressure, and altitude, Mach is the natural unit in aerodynamics where compressibility effects (M > 0.3) and shock-wave formation (M ≥ 1) become first-order design factors. This calculator uses the ISA sea-level value 343 m/s for conversion.

Mach are commonly used in automotive engineering, aviation, athletics, and meteorology.

The Meter per Second (symbol: m/s) is a unit of speed. The SI derived unit of speed (and velocity magnitude) per ISO 80000-3 §3-8, derived from the SI base units of length (meter) and time (second). m/s is the universal unit in physics, classical mechanics, fluid dynamics, kinematics, and sound propagation — every equation of motion (v = v₀ + a·t; v² = v₀² + 2·a·Δx), Bernoulli's equation, Navier-Stokes momentum equations, and ideal-gas-kinetic-theory velocity formulations assumes m/s unless explicitly stated otherwise. Reference values: human walking speed 1.2-1.5 m/s (per ISO 7176 wheelchair-accessibility studies + ADA walkway-grade limits); human running 5-12 m/s (Usain Bolt 100 m peak ~12.2 m/s; marathon pace 5.5 m/s); highway driving 25-35 m/s (60-80 mph); commercial jetliner cruise ~245 m/s (Mach 0.8 at FL350 -57 °C); speed of sound in air at sea level 343 m/s (at 20 °C, 50% RH per ISO 9613); speed of sound in seawater ~1,500 m/s (used in sonar per Mackenzie equation); speed of light in vacuum c = 299,792,458 m/s (exact per 1983 BIPM definition); Earth orbital speed around Sun 29,780 m/s; ISS orbital velocity 7,660 m/s; escape velocity from Earth surface 11,186 m/s. CFD solvers (ANSYS Fluent, OpenFOAM, STAR-CCM+) report velocity output in m/s by default in SI mode.

It belongs to the metric measurement system.

Meters per Second are commonly used in automotive engineering, aviation, athletics, and meteorology.