Rocket Nozzle Thrust Coefficient (CF) Calculator

Calculate isentropic de Laval nozzle thrust coefficients, exit pressure ratio, sea-level vs vacuum specific impulse, and Summerfield flow separation criteria.

Chamber & Ambient Pressures

Chamber Pressure Pc (psia or bar):

Ambient Atmospheric Pressure Pa (psia): 14.7 psia = Sea Level; 0 psia = Vacuum

Nozzle Expansion Area Ratio ε (Ae / At):

Gas Specific Heat Ratio γ (gamma): LOX/RP-1 ~ 1.22; LOX/LH2 ~ 1.25

Throat Dimension (Optional for Thrust)

Throat Diameter Dt (in):

Nozzle Divergence Half-Angle (°):

Thrust Coefficient & Expansion State

Thrust Coefficient (CF):

—

Vacuum CF: —

Nozzle Exit Mach Number (Me):

—

Exit Pressure Pe: — psia

Total Engine Thrust (F):

—

— kN

Expansion Regime:

—

Summerfield Flow Separation Risk:

—

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Rocket Nozzle Thrust Coefficient (CF) Calculator

Chamber & Ambient Pressures

Throat Dimension (Optional for Thrust)

Thrust Coefficient & Expansion State

Frequently Asked Questions