Performance Calculator

Turbo Boost HP Calculator

Thinking about forced induction? Estimate the horsepower you'd gain from a given boost level using the pressure-ratio method, with an efficiency factor for real-world losses.

Engine & Boost

Baseline crank horsepower with no boost.

1102030

Accounts for heat and volumetric losses. ~85–92% with a good intercooler.

Ambient pressure drops with elevation, slightly changing the ratio.

Estimated Boosted HP

266 hp

a gain of +66 hp over stock

Power Gain

+66 hp

% Increase

+33%

Pressure Ratio

1.48

Theoretical Max HP

295 hp

Reality check

This is an idealized estimate. Real gains depend on fueling, tuning, exhaust flow, and how much boost the engine can safely handle before internals become the limit.

How it works.

Ambient PSI ≈ 14.7 × (1 − alt/145000)^5.25 Pressure ratio = (Ambient + Boost) ÷ Ambient Theoretical HP = NA HP × Pressure ratio Boosted HP = NA HP × (1 + (Ratio − 1) × Efficiency)

Frequently asked questions.

Is more boost always more power?

Up to a point. Power rises with the pressure ratio, but heat, detonation limits, and airflow bottlenecks cap the useful boost. Beyond the engine's safe threshold, more boost mostly adds risk of damage rather than reliable power — which is why tuning and supporting mods matter.

Why is the efficiency factor below 100%?

Compressing air heats it, which reduces density, and no turbo system is perfectly efficient. A good intercooler recovers much of that loss, so real gains land at roughly 85–92% of the theoretical pressure-ratio number rather than the full amount.

Does altitude change the result?

Yes, slightly. At higher elevation ambient pressure is lower, so the same gauge boost represents a larger pressure ratio relative to thinner air. Forced-induction cars lose far less power at altitude than naturally-aspirated ones for this reason.