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Engine Airflow Calculator

Airflow an engine needs in CFM from displacement, RPM and volumetric efficiency.

Enter values

Results update as you type.

Result

Airflow required

190.7 CFM

In m³/min
5.4
In litres per second
90
Mass flow (at 1.2 kg/m³)
6.48 kg/min
Fuel flow at 14.7:1 AFR
0.4408 kg/min
Approximate power potential
105 hp

About the Engine Airflow Calculator

Airflow an engine needs in CFM from displacement, RPM and volumetric efficiency.

Also known as: cfm calculator engine, intake airflow, volumetric efficiency, carb size calculator.

How to use this calculator

  1. Enter displacement, engine speed, volumetric efficiency, cycle.
  2. The result updates instantly as you type — press Calculate (or Enter) at any time.
  3. Review the breakdown shown under the main result.
  4. Use Copy result or Share to save the answer or send a link with your inputs.

Formula

CFM = displacement × RPM × VE ÷ 2 (four stroke)

Worked example

Using the values pre-filled in the calculator above:

  • Displacement = 2,000 cc
  • Engine speed = 6,000 RPM
  • Volumetric efficiency = 90 %
  • Cycle: Four stroke

the calculator returns:

  • Airflow required: 190.7 CFM
  • In m³/min: 5.4
  • In litres per second: 90
  • Mass flow (at 1.2 kg/m³): 6.48 kg/min