What Is the Mach Number & Speed of Sound Calculator?
The Mach number is a dimensionless quantity representing the ratio of flow velocity past a boundary to the local speed of sound.
How Does the Mach Number & Speed of Sound Calculator Work?
Compressibility shock waves form when an object approaches or exceeds Mach 1, altering aerodynamic lift and drag.
Mach Number & Speed of Sound Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
Speed of sound a depends on adiabatic index γ (1.4 for air), gas constant R (287 J/(kg·K)), and absolute temperature T. Mach number M is velocity divided by sound speed.
How to Use the Mach Number & Speed of Sound Calculator
- Enter true airspeed in meters per second.
- Specify air temperature in Celsius.
Step-by-Step Example Calculation
Standard Atmospheric Flight
Input Values:
Understanding Your Result
Mach Number: Dimensionless flight speed ratio.
Local Sound Speed: True acoustic velocity at the specified ambient temperature.
Flow Regime: Categorized into Subsonic (<0.8), Transonic (0.8–1.2), Supersonic (1.2–5.0), or Hypersonic (≥5.0).
Factors That Affect the Result
- Ambient Temperature: High altitude cold air (-56.5°C in the tropopause) drops sound speed to ~295 m/s (~1062 km/h).
When Should You Use This Calculator?
- Aviation flight planning, compressible fluid dynamics, and supersonic wind tunnel analysis.
Assumptions & Limitations
- Treats air as a dry, calorically perfect diatomic gas (γ = 1.4).
Frequently Asked Questions
Calculation Accuracy & Reference Note
Standard compressible gas dynamics formulation.