Turbo Size Calculator
Enter a target horsepower and typical tuning parameters to estimate the compressor airflow a turbocharger needs to support it.
How turbo sizing works
Turbocharger sizing starts with figuring out how much air the engine needs to move to produce a target horsepower. This calculator uses the standard fuel-flow-based method: estimate the fuel needed for the target power using brake specific fuel consumption (BSFC), multiply by the target air-fuel ratio to get the required air mass flow, then convert that into volumetric airflow (CFM) at the target boost pressure.
Enter your target horsepower, an appropriate BSFC for your engine and fuel (0.5-0.6 lb/hp/hr is typical for boosted gasoline engines), your target air-fuel ratio, and target boost pressure.
This is a simplified reference estimate used for early-stage turbo shopping. Final compressor selection should always be checked against the specific compressor map, intake air temperature, and altitude for accuracy.