Bearing Defect Frequency Calculator (BPFO, BPFI, BSF, FTF)

Calculate exact kinematic rolling element defect frequencies for vibration spectrum analysis and peak identification per ISO condition monitoring standards.

Bearing Geometry & Operating Speed

Shaft Rotational Speed N (RPM):

Number of Rolling Elements Nb:

Ball / Roller Diameter db (mm):

Pitch Circle Diameter Dp (mm):

Contact Angle α (degrees): 0° for deep groove ball; 15-40° for angular contact

Standard Bearing Presets:

Kinematic Bearing Fault Frequencies

BPFO (Ball Pass Outer Race):

—

— CPM (—X)

BPFI (Ball Pass Inner Race):

—

— CPM (—X)

BSF (Ball / Roller Spin Frequency):

—

— CPM (—X)

FTF (Cage / Train Frequency):

—

— CPM (—X)

1X Shaft Running Speed:

—

2X BSF (Roller Spall Defect):

—

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Bearing Defect Frequency Calculator (BPFO, BPFI, BSF, FTF)

Bearing Geometry & Operating Speed

Kinematic Bearing Fault Frequencies

Frequently Asked Questions