Enter the diameter and RPM of the impeller into the calculator to determine the tip speed. This calculator can also evaluate diameter or RPM given the other variables are known.

Tip Speed Formula

The following formula is used to calculate the tip speed of an impeller.

TS = pi*D* RPM / 60
  • Where TS is the tip speed (distance/second)
  • D is the diameter of the impeller (ft / m)
  • RPM is the rotations per minute

To calculate tip speed, multiply the impeller diameter by pi, then again by the RPM, and finally divide by 60.

What is tip speed?


A tip speed is defined as the tangential velocity of an impeller at a point on its tip. The tip speed is a function of the RPM and diameter of the impeller.

An impeller is the rotating portion of a centrifugal pump, compressor, or another machine that moves fluid through rotational movement.

How to calculate tip speed?

Example Problem:

The following example problem outlines the steps required to calculate a tip speed of an impeller.

First, determine the diameter of the impeller. For this example, the diameter is measured to be 1.25 feet.

Next, determine the RPM of the pump. In this case, the pump has a running RPM of 100.

Finally, calculate the tip speed using the formula above:

TS = pi*D* RPM / 60

TS = 3.14159*1.25* 100/ 60

TS = 6.544 ft/s