Carburetor CFM Calculator
Calculate the required carburetor airflow (CFM) for your engine and get the recommended Holley/Edelbrock size.
Use the RPM at peak horsepower, not redline.
Required Airflow
462 CFM
Recommended Carb Size
390
One down
465
Best fit
500
600
650
700
750
800
850
950
1050
A 390 CFM may give better throttle response and drivability if this is a street car.
Formula: CFM = (CID × RPM × VE) / 3456
• Don't oversize significantly — a carb that's too large causes bog and poor part-throttle response.
• Going one standard size above the calculation is fine. Two sizes above is usually too much for a street car.
• For boosted engines, the formula still works — use VE > 1.0 to account for forced induction (e.g. 1.10 for mild boost).