Speed & Feed Calculators and Common Formulas
Speed & Feed Calculators
Input the required information into these Excel spreadsheet files, and the calculator will automatically provide the necessary speed and feed for your application.
| Tool Line | File Size | Revised |
|---|---|---|
| Ball Nose Finishers | 32k | Feb. 2006 |
| 90° Square Shoulder Mills & Inserts | 44k | May 2003 |
| Toroid Cutters | 48k | Dec. 2007 |
Common Formulas for Milling Operations
Download these formulas as a printable PDF file (100k).
Variables (Abbreviation)
Speed – Surface Feet per Minute (SFM)
Feed – Inches per Minute (IPM)
Feed per Tooth (FPT)
Adjusted Feed per Tooth – Chip Thinning (AFPT)
Feed per Revolution (FPR)
Depth of Cut (DOC)
Width of Cut (WOC)
Tool Diameter (D)
# of Teeth in Cutter (Z)
Metal Removal Rate – Cubic Inches per Minute (MRR)
- Speed (RPM) = SFM * 3.82 / D
- Feed (IPM) = RPM x FPT x Z
- SFM (Surface Feet per Minute) = RPM * DIA / 3.82
- IPT (Inches per Tooth) = (IPM / RPM) / Z
- MRR (Cubic Inches per Minute) = IPM * WOC * DOC
- HP (Horsepower Consumption) = MRR x mf
mf – steel = 1
mf – gray iron = .65
mf – aluminum = .3
* – 1.5% from total for every degree positive
For lead angle (chip thinning) and effective cutting diameter compensation, see corresponding tool reference page / catalog.