Boost Horsepower Calculator

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Naturally aspirated (or pre-boost) horsepower at the flywheel. Use a dyno figure if available.
hp
Gauge boost pressure - the pressure above atmospheric that the compressor adds. Street builds typically run 6-14 psi; race builds 20-35 psi.
psi
Turbochargers are exhaust-driven and generally more efficient at high boost. Superchargers are mechanically driven and have a parasitic draw on the engine.
An intercooler cools the compressed charge air, increasing its density and gaining roughly 5-10% additional power compared with running without one.
Atmospheric pressure drops with altitude. At higher elevations, you need more boost to achieve the same absolute pressure as at sea level.
Estimated boosted powerHigh boost
450hp

Predicted flywheel power with forced induction applied

Power gain200hp
Pressure ratio1.68
Boost pressure (psi)10psi
Absolute inlet pressure24.7psi
Power increase0.8%
1.68 :1
Light boost<1.2Moderate1.2-1.5High boost1.5-2Extreme2+

Estimated 450 hp with turbo boost.

  • Your turbocharger adds approximately 200 hp, bringing total output to around 450 hp.
  • A pressure ratio of 1.68 means the engine sees 1.68x more air mass than naturally aspirated.
  • Your intercooler is factored in - it densifies the charge air and reduces knock, contributing roughly 7% to the estimate.
  • High-boost builds require supporting upgrades: larger injectors, a high-flow fuel pump, upgraded head gaskets, and often forged internals.

Next stepA 79.8% power increase is typical for this boost level. Verify fuel delivery, ignition timing, and intercooler sizing before running this pressure on the street.

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