Specific Impulse Calculator

Property to Calculate:

Specific Impulse (I_sp):

Thrust (F):

Mass flow rate of exhaust (m):

Gravitational acceleration (g):

How This Is Calculated

$$ I_{sp} = \frac{F}{mg} $$ where:

I_sp = Specific Impulse (s)

F = Thrust (N)

m = Mass flow rate of exhaust (kg/s)

g = Gravitational acceleration (m/s²)

Assumptions

The engine is in steady state.
Acceleration due to gravity remains constant.
Properties of the propellant remain constant.
System is ideal.
There is no external back pressure.

Related Calculators

Rocket Equation

Rocket Equation with Gravity Loss

Rocket Thrust