Metric Feed Rate Calculator

Calculator Form

Operation

Calculation mode

Material group

Tool or work diameter

Cutting speed

m/min

Known spindle speed

rev/min

Number of teeth or flutes

Feed per tooth

mm/tooth

Feed per revolution

mm/rev

Known feed rate

mm/min

Axial depth or cut depth

Radial width

Cut length

Chip thinning or correction factor

Machine feed limit

mm/min

Specific cutting force

N/mm²

Drive efficiency

Formula Used

Purpose	Formula	Meaning
Spindle speed	n = (1000 × Vc) ÷ (π × D)	n is rev/min, Vc is m/min, and D is mm.
Milling feed rate	Vf = n × z × fz × C	z is teeth, fz is mm/tooth, and C is correction factor.
Drilling or turning feed	Vf = n × fr × C	fr is feed per revolution in mm/rev.
Cutting speed	Vc = (π × D × n) ÷ 1000	This converts diameter and spindle speed to m/min.
Machining time	Time = Cut length ÷ Vf	The result is in minutes when length is in mm.
Power estimate	Power = (MRR × Kc) ÷ 60,000,000 ÷ efficiency	MRR is mm³/min, and Kc is N/mm².

How to Use This Calculator

Select milling, drilling, or turning.
Choose the calculation mode that matches your known data.
Enter diameter, cutting speed, or spindle speed.
Enter feed per tooth for milling.
Enter feed per revolution for drilling or turning.
Add depth, width, cut length, and machine limits.
Press the calculate button to view results above the form.
Download CSV or PDF records for shop documentation.

Example Data Table

Operation	Diameter	Cutting speed	Speed	Feed input	Feed rate
Milling	10 mm	120 m/min	3819.72 rev/min	4 teeth × 0.05 mm/tooth	763.94 mm/min
Drilling	8 mm	25 m/min	994.72 rev/min	0.12 mm/rev	119.37 mm/min
Turning	40 mm	180 m/min	1432.39 rev/min	0.25 mm/rev	358.10 mm/min

Metric Feed Rate Calculator Guide

A metric feed rate calculator helps machinists choose stable motion for cutting tools. Feed rate controls tool or work movement. It links spindle speed, chip load, tooth count, diameter, and cutting speed. A good value reduces rubbing. It also avoids overload and poor finish.

Why Feed Rate Matters

Feed rate affects heat, tool wear, chip shape, surface finish, and cycle time. A slow feed can polish the material instead of cutting it. That creates heat and shortens tool life. A fast feed can break edges or overload the spindle. The best setting balances chip thickness with machine strength.

Main Inputs

The calculator uses diameter in millimeters. It also uses cutting speed in meters per minute. Spindle speed is entered in revolutions per minute. Feed values are entered in millimeters. Milling usually needs feed per tooth. Drilling and turning usually use feed per revolution. You can enter known spindle speed. You can also estimate speed from cutting speed and diameter.

Metric Method

For milling, feed per minute equals spindle speed times tooth count times feed per tooth. For drilling and turning, feed per minute equals spindle speed times feed per revolution. Cutting speed is found from diameter and spindle speed. These linked formulas make the calculator useful for planning, checking, and comparing setups.

Advanced Results

The result area shows feed rate, spindle speed, cutting speed, chip load, feed per revolution, machining time, material removal rate, and estimated power. These figures help you see the full effect of one change. Increasing diameter lowers spindle speed at the same cutting speed. Increasing tooth count raises feed rate when chip load stays fixed.

Practical Use

Start with values recommended by your tool supplier. Then adjust for machine rigidity, tool stick out, coolant, clamping, material grade, and finish needs. Use conservative settings for weak setups. Use higher values only when the sound, chip color, load meter, and surface finish are stable.

Exporting Results

Use the CSV button to save calculated data for spreadsheets. Use the PDF button for setup sheets or job records. Keep saved results with material notes, cutter details, and inspection comments. This creates a reliable history for future work. It improves repeat planning accuracy during later jobs.

FAQs

What is metric feed rate?

Metric feed rate is tool or work movement measured in millimeters per minute. It shows how quickly the cutter advances during machining.

What is feed per tooth?

Feed per tooth is the chip thickness assigned to each cutting edge. It is mainly used for milling tools with multiple teeth.

What is feed per revolution?

Feed per revolution is the linear advance for one spindle turn. It is commonly used in drilling, boring, and turning operations.

Can I use known spindle speed?

Yes. Enter spindle speed directly when your machine already has a fixed speed. The calculator will use that value before estimating speed.

Why does diameter change spindle speed?

A larger diameter covers more surface distance per revolution. At the same cutting speed, it needs fewer revolutions per minute.

What does chip factor mean?

Chip factor adjusts the feed result for special conditions. It can represent chip thinning, conservative testing, or a planned correction.

Is the power estimate exact?

No. It is an estimate based on material removal rate and specific cutting force. Real power depends on tooling, machine condition, and setup.

Why export the result?

Exported results help create setup sheets, compare trials, and keep records. They also reduce repeated manual calculations on future jobs.