Created By : Vaibhavi Kumari

Reviewed By : Rajashekhar Valipishetty

Last Updated : May 17, 2023


The Speeds and Feeds Calculator is a useful tool that calculates speed and feed rate in a matter of seconds. The tool is designed to accommodate a wide range of machine operations, and all you have to do is enter inputs and press the calculate button to receive immediate results.

Operation of Machine Tools

A cutting tool and a workpiece are included in all Machine Tool Operations. For example, if you're drilling a wood piece, the workpiece is wood. In the next courses, you will learn about numerous types of hole operations. The list is as follows

  • Drilling is the process of creating a hole in a piece of work.
  • Reaming enlarges a slightly shaped hole while leaving smooth edges.
  • Boring enlarges a hole by removing the sides.
  • Counterboring enlarges the top portion of a pre-existing hole.
  • End milling generates a long hollow in the workpiece, such as a slot or a complicated surface contour.
  • Face milling is a technique for achieving a smoother finish on a workpiece's flat surface.
  • The slab/Side Milling technique is used to create big, broad surfaces at right angles to the tool's rotating axis.

It also allows for turning operations in which the cutting tool remains stationary while the workpiece rotates. In a lathe machine, this procedure is used to create symmetric circular produced products.

Speeds and Feeds Formula

The rotating speed of the tool or workpiece is referred to as speed. There are recommended cutting or surface speeds, which can be determined using the formulas.

RPM = (12 * surface speed) / (π * tool/workpiece diameter).The speed at which the tool travels relative to the workpiece is referred to as surface speed. It is measured in feet per minute.

The diameter of the rotating element (tool/workpiece diameter) is measured in inches. When the surface speed is measured in m/sec and the diameter is measured in millimetres, the equation for calculating speed is as follows.

RPM = (60 * 1000 * surface speed) / (π * tool/workpiece diameter)

The circumference of a circle is the diameter of a tool/workpiece, according to the equation above. To calculate the rotation per minute, divide the speed at the circumference by the distance covered during one rotation (rpm).

Feeds are simply the feed rate or the relative linear speed between the tool and the workpiece. Feed Rate = RPM * chip load * number of teeth, Where RPM is the rotational speed of the rotating element.

The amount of workpiece material removed every revolution per cutting edge is referred to as chip load. The number of teeth, also known as the number of flutes, refers to the number of cutting edges on the tool.

For more concepts check out physicscalculatorpro.comto get quick answers by using the free tools available.

How can I use the calculator for speeds and feeds?

There are two modes of operation for the speeds and feeds calculator: preset mode and manual mode. You can choose the operation, tool material, tooth size and number, and workpiece material in preset mode. The calculator includes a list of suggested cutting speeds for various materials, as well as the ability to compute rotation speeds. It also provides chip load data, which can be used to compute feed rates.

You can specify the cutting speed (often in surface feet per minute - sfm) in manual mode, and it will output the rotating speed in rotations per minute (rpm), thereby converting sfm to rpm. You can also determine feed rates using custom chip loads. Next, we'll take a closer look at each mode.

Preset Mode

Follow these procedures to get your speeds and feeds using the calculator's default preset mode

  • Step 1: Choose the machine tool operation that you want to conduct.
  • Step 2: Choose between high-speed steel (often used for drill bits) or a carbide-based tool as the tool material.
  • Step 3: Choose the material for the workpiece.
  • Step 4: Enter the rotating element's diameter. This will be the tool's diameter for all operations except turning. Because the workpiece rotates during the turning operation, the workpiece diameter should be used.

The range of speeds you should employ will be displayed as a consequence. Start at the slowest speed possible and gradually increase to the average figure for the best results. Continue up to the highest speed if you want a speedy but harsh finish.

Then, to determine the range of feed rates to utilise, enter the tool's number of teeth. The feed rates displayed are based on the average rotational speed. Enter a different RPM in the custom rotation speed field to compute feed rates at a different speed. The slower the feed rate, similar to rotation speed, the smoother the operation's result.

Manual Mode

You must enter the minimum and maximum surface speeds and chip loads with the calculator mode set to manual. This information may be found on the tool's specification sheet. The following is what you should do

  • Step 1: In preset mode, enter the tool/workpiece diameter.
  • Step 2: Enter the lowest and maximum surface (or cutting) speeds, which are generally expressed in surface feet per minute (SFPM). You'll immediately see the rotational minimum and maximum speeds.
  • Step 3: Fill in the number of teeth on your instrument.
  • Step 4: For your tool, operation, and workpiece material, enter the minimum and maximum chip loads.
  • Step 5: At the average rotation speed, you'll find the minimum and maximum feed rates.
  • Step 6: You can then select a specific rotation speed for which you want to calculate the min and max feed rates, just like in preset mode.

FAQs on Speeds and Feeds

1. What is speed and average speed?

The average speed of something is calculated by dividing the total distance travelled by the total time it took to travel that distance. The definition of speed is the rate at which anything is moving at any given time.


2. What is the difference between the formula for speed and the formula for average speed?

Speed is the rate at which anything moves, whereas velocity is the rate at which something moves in a certain direction. Average speed is calculated by adding all the speeds together and dividing by the number of speeds, while average velocity is calculated in the same way.


3. What factors influence cutting speed?

Cutting speed is mostly determined by the type of material being cut and the tool being used.


4. How do I utilize the Calculator for Speeds and Feeds?

To use the Speeds and Feeds Calculator, all you have to do is select the machine's model and operation, then enter the inputs to calculate the speed and feed rate.