Aerospace Engineering / Subcategory
Propulsion
Propulsion calculators and formulas for thrust, specific impulse, and engine performance. Covers the rocket equation, thrust-to-weight ratio, and fuel consumption calculations.
31Formulas
All levels Difficulty
Updated Jul 2026
← All Aerospace Engineering (98) Propulsion (31)
Fundamental
Propeller Aircraft Range (Simplified)
R = (η_p/c_p) * (C_L/C_D) * ln(W_i/W_f)
Fundamental
Propeller Aircraft Endurance (Simplified)
E = (η_p / c_p) * (C_L^1.5/C_D) * sqrt(2*ρ*S) * (W_i^-0.5 - W_f^-0.5) / (-0.5)
Fundamental
Choked (Sonic) Mass Flow Rate
mdot = (p_c * A_t / sqrt(T_c)) * sqrt(γ/R) * (2/(γ+1))^((γ+1)/(2*(γ-1)))
Fundamental
Ideal Rocket Nozzle Exit Velocity
V_e = sqrt((2*γ/(γ-1)) * R * T_c * (1 - (p_e/p_c)^((γ-1)/γ)))
Fundamental
Overall Propulsion Efficiency
η_o = η_th * η_p
Fundamental
Brayton Cycle Thermal Efficiency
η_th = 1 - 1/(r_p^((γ-1)/γ))
Fundamental
Propulsive Efficiency
η_p = 2*V_0 / (V_e + V_0)
Fundamental
Ramjet Thrust Equation (Simplified)
F = mdot * (V_e - V_0)
Fundamental
Turbojet Thrust Equation
F = mdot * (V_e - V_0) + A_e * (p_e - p_0)
Fundamental
Thrust Specific Fuel Consumption (TSFC)
TSFC = mdot_f / T
Fundamental
Fuel Flow Rate
mdot_f = TSFC * T
Fundamental
Specific Range
SR = V / (c * T)
Fundamental
Propeller Power Coefficient
C_P = P / (ρ * n^3 * D^5)
Fundamental
Propeller Thrust Coefficient
C_T = T / (ρ * n^2 * D^4)
Fundamental
Propeller Advance Ratio
J = V / (n * D)
Fundamental
Propeller Efficiency
η_p = T * V / P_shaft
Fundamental
Power Available (Propeller-Driven Aircraft)
P_avail = η_p * P_shaft
Fundamental
Power Required for Level Flight
P_req = D * V = (C_D * q * S) * V
Fundamental
Area-Mach Number Relation (Isentropic Nozzle)
(A/A*)^2 = (1/M^2) * ((2/(γ+1))*(1+((γ-1)/2)*M^2))^((γ+1)/(γ-1))
Fundamental
Total Impulse
I_t = ∫ F dt ≈ F_avg * t_b
Fundamental
Characteristic Velocity
c* = p_c * A_t / mdot
Fundamental
Nozzle Thrust Coefficient
C_F = F / (p_c * A_t)
Fundamental
Effective Exhaust Velocity
v_e = Isp * g0
Fundamental
Rocket Mass Ratio
MR = m0 / mf
Fundamental
Tsiolkovsky Rocket Equation
Δv = v_e * ln(m0 / mf)
Fundamental
Thrust-to-Weight Ratio
T/W = Thrust / Weight
Fundamental
Breguet Endurance Equation (Jet)
E = (1/c) * (L/D) * ln(W_i / W_f)
Fundamental
Breguet Range Equation (Jet)
R = (V / c) * (L/D) * ln(W_i / W_f)
Fundamental
Rate of Climb
R/C = (T - D) * V / W
Fundamental
Specific Impulse
I_sp = F / (ṁ·g₀)
Fundamental
Rocket Thrust Equation
F = ṁv_e + (p_e − p_0)A_e