Engine CFM Calculator

Fill in the fields below (example: 5000 RPM), click calculate, and we'll show you the optimal cfm for the street and track!


Maximum Engine RPM:

Engine Size in Cubic Inches:

Volumetric Efficiency (in percentage):


Carb CFM:


About Engine CFM Calculator (Formula)

An Engine CFM (Cubic Feet per Minute) calculator is a tool used to determine the amount of air an engine is able to consume. The calculation is typically based on the engine’s maximum RPM (Revolutions per Minute), displacement (size in cubic inches or liters), and volumetric efficiency.

The formula used to calculate engine CFM is: (Maximum RPM x Engine Displacement) / 3456 x Volumetric Efficiency

The CFM rating is important for engine builders, tuners, and carburetor manufacturers because it helps them to determine the correct size of carburetor or throttle body needed to support the airflow demands of a particular engine. It also helps racers to make sure they have the right carburetor to support their engine.

CFM calculators are typically used in the automotive and motorsports industries, but can also be used in other industries such as HVAC (Heating, Ventilation, and Air Conditioning) and industrial equipment where airflow is a critical factor in the performance of the equipment.

It’s worth noting that the volumetric efficiency of a street engine is typically around 85% while racing engines are closer to 110%. This means that a racing engine can consume more air than a street engine.

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