Milling Formulas
Calculators for common milling operations
SFM
Surface Feet per Minute
Formula: RPM ÷ 3.82 x Dia = SFM
RPM
Revolutions per Minute
Formula: SFM x 3.82 ÷ Dia = RPM
IPM
Inches per Minute
Formula: RPM x IPT x #FL = IPM
IPT
Inch per Tooth, Chipload
Formula: IPM ÷ RPM ÷ #FL = IPT
IPR/FR
Inch (Feed) per Revolution
Formula: IPM ÷ RPM = IPR (FR)
MR
Metal Removal | Cubic Inches per Minute
Formula: ADC x RDC x IPM = MR
HP
Horsepower Required
Formula: IPM x RDC x ADC x PC = HP