Specific Impulse (Isp) Calculator
Calculate Specific Impulse (Isp) for rocket engines.
Specific Impulse (Isp) Calculator estimates rocket-engine efficiency from thrust and mass flow rate, or from total impulse and propellant mass. Specific impulse is the effective thrust time produced per unit weight flow of propellant; in practical terms, higher Isp means more impulse from the same propellant mass. Thrust is the force generated by the engine, mass flow rate is how quickly propellant is consumed, total impulse is thrust accumulated over burn time, and standard gravity converts propellant mass into weight for the Isp definition. The result is expressed in seconds, which can seem unusual but is standard in propulsion. This tool is useful for model rocketry, motor comparison, and propulsion coursework, but flight decisions should use manufacturer data or test-stand measurements.