💨 Boost Horsepower Calculator
Enter your engine’s naturally aspirated horsepower and the boost pressure to estimate the horsepower gain from forced induction.
What is boost horsepower?
Turbochargers and superchargers force extra air into the engine above normal atmospheric pressure, letting it burn more fuel per cycle and produce more power. This is commonly called ‘boost’ and is measured in pounds per square inch (PSI) above atmospheric pressure.
How this estimate works
This calculator uses the widely cited approximation Boost Ratio = (Atmospheric Pressure + Boost PSI) ÷ Atmospheric Pressure (using 14.7 PSI as sea-level atmospheric pressure), then multiplies your naturally aspirated horsepower by that ratio and an efficiency factor to account for real-world losses like heat and intercooler restriction.
This is a simplified estimate, not a dyno result. Actual gains depend on fueling, ignition timing, intercooling, engine internals, and tuning. Use this for general planning and educational purposes only, not as a substitute for a professional tune or dyno test.