Boost Lab, Inc. — Dade City, FL

Turbo Sizing
Calculator

Physics-based airflow analysis using BSFC methodology  |  Accurate turbo compressor map inputs
Universal Turbochargers Only — This calculator is designed for custom and aftermarket turbo builds, not direct bolt-on or OEM replacement applications. If you are looking for a drop-in replacement for your specific vehicle, contact us directly and we will point you in the right direction.
This calculator uses industry-standard BSFC (Brake Specific Fuel Consumption) formulas and thermodynamic principles to determine true airflow requirements. Results are estimates based on inputs — always validate against your turbo's compressor map and consult with a turbo specialist for final selection. Contact Boost Lab, Inc. for expert guidance.
Target Horsepower i
Engine Configuration
Displacement i
Cylinders
Valvetrain i
Peak Power RPM i
Build Intent
Fuel Type i
Application Type
Configuration
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Advanced / Conditions
Atm. Pressure i
Ambient Temp i
Intercooler Setup
A standard aftermarket air-to-air intercooler. Reduces charge temperature by approximately 75% of the difference between compressor outlet temp and ambient. Good for most street and mild track builds.
Compressor Efficiency Estimate
Used to calculate compressor outlet temperature. A well-matched modern turbo running near the center of its efficiency island typically achieves 70–75%. This affects how hot your charge air gets and how accurate the intercooler recommendation is.
Results
Required Airflow
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lb/min
Required Boost
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PSI
Pressure Ratio
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:1 absolute
Est. Airflow (CFM)
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volumetric at inlet
Vol. Efficiency
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% estimated
BHP Target
—
crank horsepower
NA Airflow (Peak)
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lb/min unforced
Thermal Analysis
Compressor outlet temperature and charge density are calculated using the isentropic compression formula with your assumed compressor efficiency. Intercooler effectiveness reduces charge temp before the intake manifold.
Inlet Temp (T1)
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Compressor Outlet (T2)
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Post-IC Temp (T3)
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Temp Rise
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Turbo Frame Size
Based on total system airflow demand. Use this to identify the right compressor wheel class when reading compressor maps.
MicroSmallMediumLargeXLXXLRace
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Airflow Demand Across RPM Range
Stage RPM NA Flow (lb/min) Boosted Flow (lb/min) CFM (Boosted) % of Target
Airflow vs RPM
Dashed line: naturally aspirated. Solid line: boosted at required pressure ratio. Horizontal line: required airflow for target power.

Build Assessment

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