Machining Speeds & Feeds Calculator
A free, browser-based calculator. Runs entirely in your browser — no sign up, nothing stored.
Enter Values
How to use this calculator
- Enter the cutting (surface) speed Vc in m/min for your material and tool.
- Enter the tool or workpiece diameter (mm).
- Optionally add the feed per tooth and the number of teeth/flutes to get a feed rate.
- Read the spindle speed (and feed rate).
How it works
Spindle speed comes from the surface speed and diameter: n = 1000 · Vc / (π · D) rpm.
Feed rate is then feed = n · fz · z, where fz is the feed per tooth and z the number of teeth/flutes — used for milling and drilling feed setting.
Worked example
Vc = 120 m/min, 10 mm cutter. n = 1000 × 120 / (π × 10) ≈ 3820 rpm. With fz = 0.05 mm and 4 flutes, feed ≈ 3820 × 0.05 × 4 ≈ 764 mm/min.
Tips
- Use the cutter diameter for milling, and the workpiece diameter for turning.
- Start conservative and increase — listen to the cut and watch tool wear.
Frequently asked questions
Where do I get the cutting speed?
From the tool maker's data for the material/tool combination (e.g. mild steel with HSS vs carbide differ a lot). The values here are a starting point — fine-tune for finish, rigidity and tool life.
Can I use these results for final design?
No. These calculators are for first-pass sizing, checking and learning. They assume ideal supports, static loads and elastic behaviour, and they don't apply load factors, member capacity, buckling or connection checks. Always verify against the relevant design code (e.g. AS 4100, AS 1170, Eurocode) and have a qualified engineer sign off structural work.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.