# Pump GPM Calculator

Flow Rate (GPM):

## What is Pump GPM?

GPM stands for gallons per minute, and it is a unit of flow rate that is commonly used to describe the flow rate of liquids, including water. The flow rate of a pump is the volume of liquid that the pump is capable of moving per unit of time.

**Note:** This formula is an approximation and is only valid for pumps that are operating at or near their best efficiency point (BEP). For pumps that are operating outside their BEP, the flow rate may be significantly different.

It is also important to note that the actual flow rate of a pump can vary based on a number of factors, including the viscosity and density of the liquid being pumped, the pump’s suction and discharge conditions, and the pump’s design and operating conditions.

## Pump GPM Calculation Formula

To calculate the flow rate of a pump in GPM, you will need to know the following information:

- The speed of the pump (measured in revolutions per minute, or RPM)
- The diameter of the pump impeller (the component that moves the liquid)
- The distance that the liquid is being pumped (referred to as the “head”)

Once you have this information, you can use the following formula to calculate the flow rate of the pump in GPM:

**Flow rate (GPM)** = (pump speed (RPM) * impeller diameter (inches)^3) / (total head (feet) * 3960)