💨 Isentropic Flow Calculator
Calculate stagnation-to-static temperature and pressure ratios for isentropic compressible flow at a given Mach number.
What isentropic flow relations describe
Isentropic flow relations describe how temperature, pressure, and density change between the stagnation (zero-velocity, e.g. inside a reservoir) and static (moving-flow) conditions in compressible gas flow, assuming no friction or heat transfer (an idealized, reversible, adiabatic process).
The formulas
Temperature ratio T0/T = 1 + ((γ-1)/2)M², pressure ratio P0/P = (T0/T)γ/(γ-1), and density ratio ρ0/ρ = (T0/T)1/(γ-1), where M is the Mach number and γ is the gas’s specific heat ratio (1.4 for air).
These are the standard compressible flow (gas dynamics) isentropic relations used in aerodynamics and propulsion engineering references.
Last reviewed August 2026