Feed & Speed Calculator
Calculate spindle RPM and feed rate from cutting speed, diameter, flute count and chip load.
Open tool →CNC calculation tools
Feed & Speed Calculator
Calculate spindle speed, feed rate, chip load and cutting speed, then use the supporting machining references to check the result before it reaches the machine.
Metric and imperial support. Results are mathematical starting points, not manufacturer cutting-data recommendations.
Quick Feed & Speed
Enter cutting speed, diameter, flute count and chip load.
Feed Speed
Enter the values you know. The result is calculated in your browser.
Calculation only. Verify toolmaker data, material grade, engagement, machine limits, workholding and actual cutting conditions before production.
Calculator library
Choose the calculation you actually need
Use the dedicated calculator for the variable you are checking. Every tool shows its inputs, formula relationship and result instead of hiding the arithmetic.
Spindle Speed Calculator
Calculate spindle speed from cutting speed and tool diameter.
Open tool →Feed Rate Calculator
Calculate feed rate from RPM, flute count and chip load per tooth.
Open tool →Chip Load Calculator
Calculate chip load per tooth from feed, RPM and flute count.
Open tool →SFM Calculator
Calculate surface feet per minute from spindle speed and diameter.
Open tool →Cutting Speed Calculator
Calculate cutting speed from RPM and cutter diameter.
Open tool →MRR Calculator
Estimate material removal rate from feed and cutting engagement.
Open tool →Feed per Revolution
Convert feed rate and RPM into feed per revolution.
Open tool →Cutting Time Calculator
Estimate cutting time from distance and programmed feed.
Open tool →Machining operations
Calculators and references by operation
Milling, turning, drilling and tapping have different variables. Start with the operation, then open the calculation or reference page that matches the job.
CNC Milling
Feeds and speeds, chip load, MRR, step-over, engagement and practical milling setup notes.
Open tool →CNC Turning
Spindle speed, cutting speed, feed per revolution and turning setup references.
Open tool →CNC Drilling
Drill RPM, feed per revolution, hole depth and drilling setup guidance.
Open tool →CNC Tapping
Tap speed, pitch, feed synchronization and tapping-cycle references.
Open tool →Materials
Material families, machining behavior, reference ranges and related tools.
Open tool →Charts & Formulas
Reference tables and formula explanations for common CNC calculations.
Open tool →Technical reference
Calculation first. Context second.
The site is built around the way machinists actually use these numbers: calculate, check the assumptions, compare with tooling data, then validate the cut.
Materials Reference
Read practical notes on aluminum, steel, stainless, titanium, brass, cast iron and engineering plastics.
Open tool →Machining Guides
Step-by-step explanations for feed rate, chip load, SFM, RPM, MRR and setup checks.
Open tool →Machining Articles
Detailed technical articles covering calculations, troubleshooting and cutting-data interpretation.
Open tool →How to use the calculators
Start with the value that is known from the tooling documentation or the machining plan. For a feed and speed calculation, that normally means cutting speed, tool diameter, flute count and chip load. For an RPM calculation, the required inputs are cutting speed and diameter. For feed rate, the relationship is RPM multiplied by flute count and chip load per tooth.
Keep the units consistent. Metric cutting speed is normally expressed in metres per minute with diameter in millimetres. Imperial cutting speed is expressed as surface feet per minute with diameter in inches. Mixing those systems without a conversion changes the result by a large factor.
Step 1 — identify the actual tool
Record the tool diameter, number of cutting edges and relevant geometry. A catalogue description is more useful than a generic cutter category because coatings, flute geometry, corner treatment and tool length can affect the recommended cutting data.
Step 2 — enter the published starting data
Use the cutting speed and chip-load range supplied for the material and actual tool whenever it is available. The calculator should perform the arithmetic; it should not replace the source data that defines the intended cutting condition.
Step 3 — check machine and setup limits
Compare calculated RPM with the spindle rating and feed with the machine control. Then check stick-out, workholding, radial and axial engagement, coolant delivery and chip evacuation. These physical conditions are outside the calculator formula but directly affect the cut.
Step 4 — validate the first cut
Make a controlled test and watch spindle load, chip shape, sound, surface finish and tool condition. If an adjustment is needed, change one major variable at a time and record the result. A proven cutting condition is more useful when the inputs and observations are documented.
Production check A calculated number is not a guarantee of a safe or productive cut. Always compare it with the toolmaker's data and the actual machine, tooling, material and workholding conditions.
Latest technical reading
Detailed articles and practical notes
Long-form reference material is connected directly to the calculators so the page you read can lead back to a useful tool.
How to Calculate CNC Feed Rate
A practical walkthrough of RPM, flute count, chip load, unit handling and validation.
Read article →Chip Load Explained
Understand chip load per tooth, what changes it and how to troubleshoot a poor result.
Read article →How to Read Feed and Speed Charts
Use published cutting data without treating a reference table as a universal recipe.
Read article →Frequently asked questions
Are the calculator results production recommendations?
No. They are mathematical calculations based on the inputs supplied. Manufacturer cutting data, material condition, tool geometry, engagement, machine capability and workholding must be checked separately.
Why are there separate calculators?
Separating RPM, feed, chip load, SFM and MRR keeps each calculation transparent and makes it easier to audit the inputs.
Can I use metric and imperial units?
Yes. The calculator interfaces provide separate unit modes. Keep the inputs internally consistent when checking a result.
Where should I start if I am unsure which calculator to use?
Open the calculator library. It lists the tools by calculation and links the related machining references.
Need a number? Start with the calculation.
Use the dedicated calculator, then follow the linked reference material to check the assumptions behind the result.
Browse all calculators →