Milling Process Calculations; Formulas, Calculators, Explanations

Milling processes are very important for the manufacturing industry. Among the other manufacturing processes milling operations has a very important place. So, we explain the general process calculations of milling operations. Also, you can make the milling process calculations with the calculator. You can also utilize the explanations of milling process formulas.

Types of peripheral milling operations.
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Calculations of Milling Process Parameters

Firstly, you can find the explanations of the milling process parameters and calculations here.

Cutting Speed of Milling Processes

As you know that the cutting speed is the primary motion in the machining processes. So, calculation of the cutting speed is very important to show lots of other parameters. And the formula of the cutting speed in milling operations;

RPM formula of milling operations.

And also, according to the formula, ‘N’ is the cutting speed of the cutting tool. It states the revolution per minute of the cutting tool in the milling operation. In other words, there is a direct relationship between the chip removal rate and the cutting speed.

Also, ‘V’ is the speed of the outside diameter of the cutting tool. And then, it has the unit of ft/s or m/s in SI units. And ‘d’ is the diameter of the cutting tool. The unit of the cutting tools is ft or m in SI units.

So, as you understand from this formula, with the increasing ‘V’ the cutting speed of the cutting tool increases in the milling process. Also, with the increasing ‘d’, the cutting speed decreases.

Feed Rate

Feed rate is another important parameter in milling process calculations. And also, feed rate depends on the chip load of the cutting tool. Chip load means the total chip that is removed by one tooth in milling operations. We are using this formula in the calculation of feed rates of milling operations;

Feed rate formula of milling operations.

According to this formula, ‘Fr’ is the feed rate which has the unit of in/min or mm/min in SI units. ‘N’ is the rotational speed of the cutting tool which has the unit of RPM, ‘it’ is the number of teeth of the cutting tool and the ‘f’ is the chip load of the cutting tool.

So, as you see in the feed rate formula of the milling operations, there is a direct correlation between all the parameters with the feed rate. And also, with the increasing RPM, ‘nt’ and ‘f’ the feed rate of the milling operation increases.

Material Removal Rate

The material removal rate is also a very important parameter of milling process calculations. This parameter shows how much material is removed in a minute in a milling operation. So, this formula calculates the material removal rate of the milling operation;

Material removal rate.

In this formula, ‘w’ is the width of the cutting tool which has the unit of in or mm in SI units. And also, ‘d’ is the depth of cut which has the unit of in or mm in SI units in milling process calculations.

So, with the increasing width and the depth of cut, the material removal rate increases. And the increasing feed rate, the material removal rate also increases.

Calculation of Total Milling Time

This is a very important parameter in milling operations. Total time is one of the most important parameters that a process consumes. So, the calculation of milling time is very important. With this formula, we can calculate the total milling time;

Calculation of total milling time in milling process calculations.

So, in this formula, ‘L’ is the length of the workpiece which has the unit of in or mm. And also, ‘Fr’ is the feed rate and the ‘A’ is the approach distance of the cutter to the workpiece in milling process calculations.

With the increasing approach distance and the length of the workpiece, the total milling time increases. Furthermore with the increasing feed rate, the total milling time decreases.

What is Approach Distance and How to Calculate It?

Approach distance is the parameter that the total distance that the cutter engages to the workpiece. So, to the total length of the workpiece, we must add this value to find the total time exactly. Also, the calculation of the approach distance is somewhat different in milling process calculations.

We calculate the approach distance according to the milling operations; face milling or peripheral milling process.

For peripheral milling operations, we use this equation to calculate the approach distance;

Approval distance in peripheral milling.

According to this formula, ‘d’ is the depth of cut and the ‘D’ is the diameter of the cutter in milling process calculations.

For the face milling operations, there are two possible scenarios. If the diameter of the cutter is bigger than the total width of the workpiece(D>w), we use this approach distance formula;

Approval distance in face milling.

And, if the width of the workpiece is bigger than the diameter of the cutting tool(w>D), we calculate the approach distance with this formula also;

Approval distance in face milling.

Milling Process Parameters Calculator

We prepared a special calculator to calculate all the parameters indicated above. So, you can use this calculator in different milling process calculations without any problem. Also, you may have lots of calculations at hand related to the milling operation. You can use the calculator below to save time during these calculations.

Face Milling Operations Calculator

Side Milling Operation Calculator

Other Milling Operation Calculator

Furthermore, the use of the milling process calculator to calculate milling process calculations is very simple. In addition, you just need to enter the values of;

  • Cutting speed of outer diameter of the cutting tool(ft/s)
  • Diameter of the cutter(in)
  • The chip load(Unitless)
  • Number of teeth
  • Width of the workpiece(in)
  • Depth of cut(in)
  • Length of the workpiece(in)

After that, you need to click on the ‘Calculate!’ button to calculate the parameters of;

  • Cutting speed(RPM)
  • Feed Rate(in/min)
  • Material Removal Rate(in^3/min)
  • Total Machining Time(min)
  • Approach Distance(in)

If you want to make further milling process calculations, you can click on the ‘Reset’ button and re-enter the values.


So, the general explanations of the milling process are calculations like this. There are lots of parameters that affect the milling operations. Total machining time is also a very important parameter to calculate. The milling process calculator is also a very useful calculator for seeing all the parameters in one aspect.

Above all, Mechanicalland does not accept any responsibility for calculations made by users in calculators. A good engineer must check calculations again and again.

Also, you can find out much more calculators like this in Mechanicalland! Take a look at the other engineering calculators available in Mechanicalland!

Finally, do not forget to leave your comments and questions below about milling process calculations and machining operation calculators.

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