What is the M (Mach Number)?
The Mach number is an object's speed divided by the local speed of sound. It tells you whether compressibility effects matter — subsonic below 0.8, transonic near 1, supersonic above 1.2, and hypersonic above 5.
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Mach Number Calculator
Compute the Mach number from speed, air temperature and gas properties to classify flight as subsonic, transonic, supersonic or hypersonic.
M = v ÷ √(γ·R·T)
Frequently asked questions
Can you show a worked example?
v=340, γ=1.4, R=287, T=288 → a=√(1.4·287·288)=340.2 → M ≈ 1.0 → Transonic.
How do I read the graph?
The visualisation places your computed M against colour-coded regime zones, with a live marker so you can see at a glance which flow or transfer regime your inputs fall into and how close you are to the next threshold.
Where is this used in real life?
Aircraft and missile design, wind-tunnel testing and compressible-flow analysis.
What are the limits or edge cases?
All inputs must be physically valid; a zero in the denominator (e.g. zero viscosity, velocity or conductivity) is rejected rather than producing infinity. Regime thresholds are standard textbook values and can shift with geometry and conditions.