`eta_j = P_a / P_j `

Enter a value for all fields

In aircraft and rocket design, overall propulsive efficiency `eta` is the efficiency, in percent, with which the energy contained in a vehicle's propellant is converted into useful energy, to replace losses due to air drag, gravity, and acceleration

The equation to calculate this is expressed as

`eta_j=P_a/P_j` 

where:

• `P_a` is the available engine power. This is the power that does the actual work.
• `P_j` is the jet power.