CNC Machining Calculators
Free tools for cutting speed, spindle speed, feed rate and material removal rate. Nothing to install, nothing to sign up for. We use these calculations every day in our own shop in Ankara.
These calculators do the arithmetic only. Cutting speed and feed values depend on the material, the tool, the coolant and the rigidity of the setup — always use the values recommended by your tool supplier.
Milling
Enter tool diameter and cutting speed to get spindle speed. Add teeth and feed per tooth for feed rate, then depths of cut for material removal rate.
n = Vc × 1000 / (π × D) · Vf = fz × z × n · Q = ae × ap × Vf / 1000Turning
Enter workpiece diameter and cutting speed to get spindle speed, then feed per revolution for feed rate.
n = Vc × 1000 / (π × D) · Vf = f × nDrilling
Enter drill diameter and cutting speed to get spindle speed, then feed per revolution for feed rate.
n = Vc × 1000 / (π × D) · Vf = f × nUnit converter
Frequently asked questions
How do I calculate spindle speed from cutting speed?
Spindle speed n (rpm) = Vc × 1000 / (π × D), where Vc is the cutting speed in metres per minute and D is the diameter in millimetres. For milling, D is the tool diameter; for turning, it is the workpiece diameter.
How do I calculate feed rate for milling?
Feed rate Vf (mm/min) = fz × z × n, where fz is feed per tooth in millimetres, z is the number of teeth on the cutter and n is the spindle speed in rpm.
How is material removal rate calculated?
For milling, Q (cm³/min) = ae × ap × Vf / 1000, where ae is the radial depth of cut, ap the axial depth of cut, both in millimetres, and Vf the feed rate in mm/min.
How do I convert m/min to SFM?
Multiply metres per minute by 3.2808 to get surface feet per minute. To go the other way, divide SFM by 3.2808.
Which cutting speed should I use?
That depends on the material, the tool grade and coating, the coolant and how rigid the setup is. These calculators do not recommend values; use the data sheet from your tool supplier and adjust from there.
Need the part made, not just the numbers?
We machine precision parts on 5-axis and Swiss-type machines in Ankara, Türkiye. Send your technical drawing and we will review it for manufacturability and quote it.
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