Pump Efficiency Calculator

Input the required values in the boxes of this Pump Efficiency Calculator and hit calculate button to find the efficiency of the pump.


Know how efficiently your pump works by using the Pump efficiency calculator online. 

Users can easily find the productivity of their pump through this tool if they know the WHP and BHP of their plant. 

Other than that, this calculator can find the third value if the other two are provided. For instance, you can find BHP on inputting the WHP and pump efficiency.

To know more about this topic in detail, stay tuned. But before that, below is a brief guide to using the pump efficiency calculator.

What is Pump efficiency?

The definition of Pump efficiency is.

     “The ability of the pump to convert one energy to another form.
            “The ratio between the input and output of the pump.

But to actually find this ratio is a difficult task. Multiple questions arise like what are the output and input values, what are their names, and how to compute them.

Don’t worry, we have narrowed it down for you to make it comprehensible.

Basically, pump efficiency accounts for the productivity or the potential of a pump. It tells how much energy provided as input to your pump is actually yielded as output.

A 100 percent efficient pump is non-existent, the one that converts the full Input into the output. The value of its ratio would be 1. It is because some of the energy will always be wasted in the form of friction or leakage or from any other complex reason.

This means the output value of the pump is always less than the input value. The AC induction motors can reach an efficiency of 99 percent but usually, the efficiencies are 55 and 70 percent for the small and large pumps respectively.

Fundamentally, Pump efficiency depends on the Water horsepower and the Brake horsepower. 

View another energy-related tool; Horsepower calculator.

Water Horsepower (WHP):

This is our output value. Water horsepower can be defined as the minimum energy or power required to move the water or the fluid. 

It is the energy required by a 100 percent efficient pump to reach the hydraulic conditions. 

If you don't already know the WHP, use the Water horsepower calculator.

Brake horsepower (BHP):

Brake horsepower is the input value in this case. This is the energy that, in ideal conditions, the pump would have delivered. It defines the capacity of the pump. 

But as mentioned before, there are different types of energy losses during this process.

Find the BHP from the Brake horsepower calculator.

Pump efficiency formula/ratio:

This ratio can be found written in different ways. For example WHP to BHP, power output to the power input, or work output to the work input.

Essentially, all of these ratios tell the same thing. 

Pump efficiency = Water horsepower / Brake horsepower

You can find the percentage of this ratio by multiplying it by a hundred.

How to find the pump efficiency?

Links to all of the tools that can assist in the pump efficiency calculation have been added above. To find it by hand, you can follow the detailed guide given below.

  1. Find the flow rate, Total head, and specific gravity.
  2. Multiply these values and divide by 3960 to find WHP.
  3. Multiply the torque and speed and divide it by 3960 to find BHP.
  4. Now find the ratio between these two values.

What is the pump efficiency if WHP is 40 and BHP is 70?


Step 1: Write the given data.
Water horsepower = 40 hp
Brake horsepower = 70 hp

Step 2:  Make the ratio and solve. 
= WHP / BHP 
= 40 / 70
= 0.57 

Why do we need to calculate pump efficiency?

It is important to find the efficiency before buying a pump at an individual level or installing a plant at an industrial or higher level. An efficient pump will save fuel sources and the budget cost. 

Typically, an inefficient pump will cost 5 to 10 times more than the original cost including installation after a few years. 

This is why it becomes absolutely necessary to know if the resources are being used at the right gadget.

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