Chip Load & Material Removal Rate
Feed rate from chip load, flutes and rpm (or chip load from a feed rate), rpm from cutting speed, material removal rate and power — milling, turning, drilling.
Spindle speed, feed rate or chip load, feed per revolution, MRR in cm³/min or in³/min, the chip-thinning factor when the radial width is under half the diameter, and power from your specific cutting force.
Example: A Ø10 four-flute end mill at 150 m/min and 0.05 mm per tooth: 4,775 rpm, 955 mm/min; at 5 deep and 3 wide the MRR is 14.3 cm³/min, and chip thinning suggests 0.0546 per tooth.
Speeds and feeds,
just the arithmetic.
How rpm, feed rate, chip load and MRR relate, and what chip thinning does.
Speed and feed
Spindle speed follows from the surface speed: n = 1000·vc ÷ (π·D) with vc in m/min and D in mm (12·vc ÷ (π·D) with sfm and inches). Milling feed rate vf = fz × z × n — chip load per tooth times flutes times rpm — and the same equation solved backwards gives the chip load a programmed feed rate really delivers. Turning and drilling use feed per revolution: vf = f × n.
Removal rate and power
MRR is the volume removed per minute: ap × ae × vf for milling, vc × f × ap for turning, π·D²/4 × vf for drilling — in cm³/min or in³/min. With a specific cutting force kc (N/mm²) from your material data, power at the cut ≈ MRR × kc ÷ 60 000 kW (imperial: MRR × unit power in hp·min/in³); spindle efficiency and tool wear add to it.
Chip thinning
When the radial width of cut is under half the cutter diameter the tooth never reaches the full chip thickness; the average thickness is reduced by the factor √(1 − (1 − 2ae/D)²). To keep the chip you programmed, divide the chip load by that factor. All vc, fz and kc values are yours from the tool and material data sheets — the page embeds no tables. Nothing leaves the browser; the same four anonymous usage counts as the rest of the site apply.
SOURCES
- n = 1000·vc/(π·D); vf = fz × z × n; MRR = ap × ae × vf (milling), vc × f × ap (turning), π·D²/4 × f × n (drilling); chip thinning √(1 − (1 − 2ae/D)²); P = MRR × kc ÷ 60,000 — no material tables
Last reviewed 20 September 2026. How results are checked: How we verify.