m/min to SFM Calculator
Convert cutting speed from meters per minute to surface feet per minute, then check the matching RPM, diameter, material range, tool recommendation, and feed estimate.
1 Shop presets
Load a common machining setup, then fine tune diameter, RPM, tool style, chip load, and safety derate.
2 Speed converter and reverse check
3 Results
Calculation breakdown
4 Material and tool grid
5 Reference tables
These ranges are conservative starting values for common shop tooling. Adjust for machine rigidity, tool coating, stickout, coolant, and manufacturer data.
| Material | HSS m/min / SFM | Carbide m/min / SFM | Starting note |
|---|---|---|---|
| Aluminum 6061/7075 | 90-150 / 295-492 | 180-365 / 591-1,198 | Use polished flutes or high rake and clear chips aggressively. |
| Mild steel 1018/A36 | 25-35 / 82-115 | 55-120 / 180-394 | General baseline for drilling, milling, and turning on rigid machines. |
| Stainless 304/316 | 15-22 / 49-72 | 30-75 / 98-246 | Avoid dwell; lower speed if the tool rubs or the work hardens. |
| Gray cast iron | 25-45 / 82-148 | 90-180 / 295-591 | Abrasive dust and interrupted cuts often justify conservative speed. |
| Tool steel D2/O1 | 12-20 / 39-66 | 30-75 / 98-246 | Reduce speed for hardened stock, long stickout, or small tools. |
| Brass/bronze | 75-120 / 246-394 | 120-220 / 394-722 | Free-cutting brass can run fast, but grabby tools need geometry care. |
| Titanium Ti-6Al-4V | 8-15 / 26-49 | 25-55 / 82-180 | Heat stays in the edge; use sharp carbide and stable coolant. |
| Engineering plastic | 120-250 / 394-820 | 180-450 / 591-1,476 | High chip clearance and low heat prevent melting and rewelding. |
| Tool type | Speed factor | Chip guidance | Best use |
|---|---|---|---|
| HSS drill | 0.55x | Lower SFM, steady feed | Manual drilling and small shop machines. |
| Carbide drill | 1.05x | Needs rigidity and coolant | Production holes with short tools. |
| Carbide end mill | 1.15x | Use chip load, not rubbing | Milling aluminum, steel, plastic, and wood. |
| Micro end mill | 0.70x | Keep runout tiny | Small diameter work where breakage risk is high. |
| Face mill | 1.05x | Watch insert load | Wide cuts with multiple inserts and stable fixturing. |
| Turning insert | 1.00x | Diameter changes SFM | OD turning, facing, boring, and profiling. |
| Router bit | 1.20x | Chip evacuation first | Wood, plastic, composites, and high-speed spindles. |
| Reverse check | Formula | Metric example | Imperial example |
|---|---|---|---|
| m/min to SFM | SFM = m/min x 3.28084 | 240 m/min = 787 SFM | Input is already SFM |
| SFM to m/min | m/min = SFM x 0.3048 | Input is already m/min | 650 SFM = 198.1 m/min |
| Target RPM | RPM = speed / circumference | 240000 / (pi x 12 mm) = 6366 RPM | 787 x 12 / (pi x .472 in) = 6366 RPM |
| Actual speed | speed = pi x D x RPM | pi x 12 mm x 6000 / 1000 = 226 m/min | pi x .472 in x 6000 / 12 = 742 SFM |
| Feed estimate | RPM x teeth x chip | 5729 x 3 x .09 = 1547 mm/min | 5729 x 3 x .0035 = 60.2 IPM |
| Preset setup | Diameter | Speed | Shop check |
|---|---|---|---|
| 6061 carbide end mill | 12 mm / 0.472 in | 240 m/min / 787 SFM | High speed spindle, strong chip evacuation. |
| HSS drill in mild steel | 9.5 mm / 0.375 in | 24 m/min / 79 SFM | Good drill press baseline with cutting oil. |
| 304 stainless turning | 32 mm / 1.260 in | 45 m/min / 148 SFM | Keep the insert cutting; avoid dwell. |
| Cast iron face mill | 50 mm / 1.969 in | 135 m/min / 443 SFM | Dust control and insert condition are important. |
| Titanium roughing | 10 mm / 0.394 in | 35 m/min / 115 SFM | Limit heat and use conservative engagement. |
6 Tips and safety
The speed at which the cutting edge travel across the piece of material in one minute is known as the surface speed. The unit in which the surface speed is measured can be meters per minute, but you can also measure the surface speed in surface feet per minute. Although both of these unit indicate the same motion, different individual use different units when they measure this value.
In cases in which the machines is set to use surface feet per minute instead of meters per minute, it is necessary to convert the values of meters per minute to surface feet per minute. To perform this conversion, multiply the value in meters per minute by 3.28 in order to obtain the value in surface feet per minute. You can reverse the process in order to determine the number of meter per minute in a value in surface feet per minute.
Surface Speed: What It Is and How to Set It
The calculation of the surface speed is important in relation to the tool that is being used and the parts that is produced. If the calculated value of the surface speed is too high, the tool will not last as long as it should, and the part will have a smeary appearance to it. If the value of the surface speed is set at the correct value, the tool will last more longer, and the parts will be produced with a clean appearance.
It is difficult to calculate the correct value for the surface speed due to the number of factor that can influence the speed at which the cutting tool should travel. The type of material that is being cut has an influence upon the correct value of the surface speed. The material of the tool has an influence upon the speed at which the tool should travel.
The type of operation that is performed with the tool has an influence upon the speed at which the tool should travel. The amount of coolant that is used has an influence upon the speed at which the tool should travel. For instance, if the tool material is carbide, then the speed is likely to be higher for operations in which aluminum is being cut than for the cutting of stainless steel with that same type of tool.
Diameter is one of the factors that is considered when determining the value of the surface speed. The relationship between the surface speed and the spindle speed is related to the circumference of the tool or the workpiece. The diameter of the tool impact the spindle speed in revolutions per minute so that the surface speed of the tool remains the same.
A small diameter tool will have a lower surface speed then a large diameter tool if both tools are spinning at the same rate in revolutions per minute. Thus, the diameter of the cutting tool is another factor that must be considered when setting the speed of the cutting tool. The feed rate of the cutting tool is another measurement that is performed after the spindle speed is established.
Once you have established the revolutions per minute for the tool, you can determine the feed rate by considering the number of tooth that the tool has and the chip load per tooth of that tool. The chip load per tooth is the amount of material that each tooth of the cutting tool removes during one revolution of the tool. The safe chip load per tooth will vary according to the material that is being cut and the type of operation that is being performed with the tool.
For instance, the chip load per tooth will be less for slotting operations than for peripheral cutting operations. The rigidity of the setup will also impact the feed rate; setups that have low rigidity will require a lower feed rate than setups with high rigidity. Many shop will not operate at the highest possible rates for the surface speed of the tool.
There are several factors that may require that rate to be lower than the maximum surface speed rate. Factors such as the type of tool coating will impact the rate at which the tool should travel. The stiffness of the machine and the quality of the workholding setup will impact the rate at which the cutting tool should travel.
The type of coolant that is used during the cutting operations will impact the rate at which the cutting tool should travel. For instance, if flood coolant or through-tool coolant is used, the surface speed can be increased relative to dry or mist coolant condition. Calculators are available that will permit the establishment of a safety derate for the tool relative to these factor.
These calculators will also display the effect that a reduction in the surface speed will have upon the RPM and the feed rate for the tool. A common mistake is to not consider the variables that impact the rate at which the tool should travel. The published surface speed for a tool for a specific type of material is merely a starting point for the rate at which the tool should travel.
As such, adjustments must be made to the published value of the surface speed according to the machine, the tool, and the part that is being manufactured. A reverse calculation can be made for the existing setup to ensure that the surface speed is not too high or too low. Thus, calculating the surface speed for the tool prior to the start of the cutting operation is a useful step in the manufacturing process.
