Carburetor CFM Calculator

Estimate required carb CFM from engine displacement (CID), peak RPM, and volumetric efficiency (VE).

Result:
Enter values and click Calculate.
Notes
  • Street VE often ranges 0.80–0.90; performance builds may be higher.
  • CFM is a guideline—multi-carb setups, altitude, and cam profile affect choice.

Common Carburetors Reference

Stromberg

Stromberg 97

CFM: ~150–165 CFM
Years: 1934–1938

Stromberg 48

CFM: ~175 CFM
Years: 1934

Stromberg 81

CFM: ~125 CFM
Years: 1937–1941

Holley

Holley 94

CFM: ~155–185 CFM
Years: 1938–1957

Holley 4150 / 4160

CFM: 390–850 CFM
Years: 1957–present

Holley 4000 "Teapot"

CFM: ~400 CFM
Years: 1952–1957

Carter

Carter WCFB

CFM: 350–450 CFM
Years: 1952–1967

Carter AFB

CFM: 400–625 CFM
Years: 1957–1971

Carter AVS

CFM: 500–650 CFM
Years: 1966–1970

Rochester

Rochester 2G / 2GC / 2GV

CFM: 245–500 CFM
Years: 1955–1979

Rochester Quadrajet (Q-Jet)

CFM: 600–800 CFM
Years: 1965–1990

Rochester Model B (1-Barrel)

CFM: ~150–200 CFM
Years: 1950–1967

Ford / Autolite / Motorcraft

Autolite 1100

CFM: ~185 CFM
Years: 1963–1969

Autolite 2100 / 2150

CFM: 190–424 CFM
Years: 1957–1974 (2100), 1974–1986 (2150)

Autolite 4100

CFM: 480 or 600 CFM
Years: 1957–1967

Weber

Weber 32/36 DGV

CFM: ~300 CFM
Years: 1960s–present

Weber 45 DCOE

CFM: Variable (choke-dependent)
Years: 1953–present