Water Pump Size Calculator Online
Calculate pump head, power, flow velocity and recommended pipe diameter for water pumping systems.
Pump Sizing Calculator
Estimate total dynamic head, pump power, flow velocity and recommended pipe diameter for industrial, agricultural and solar water pumping systems.
* Preliminary calculation for clean water. Final pump selection should be checked against the pump performance curve, pipe material, fittings, water temperature, NPSH and required safety margin.
Get Pump Selection HelpRecommendation
Please enter your system requirements to see the recommended pump type.
How to Use This Water Pump Size Calculator
Use this calculator to get a quick reference for pump sizing before selecting a pump model.
Enter the Flow Rate
Input the required water flow rate for your system. You can choose common units such as m³/h, L/min or GPM.
Add the Vertical Lift
Vertical lift is the height difference between the water source and the discharge point. This is an important part of the total dynamic head.
Enter Pipe Length and Pipe Diameter
Pipe length and pipe diameter affect friction loss. A smaller pipe diameter can cause higher flow velocity and greater pressure loss.
Add Outlet Pressure
If your system requires pressure at the discharge point, enter the required outlet pressure in bar.
Adjust Pump Efficiency
Pump efficiency affects the estimated motor power. If you do not know the actual pump efficiency, 65% can be used as a general reference value.
Review the Results
The calculator will show total dynamic head, estimated pump power, flow velocity and a recommended reference pipe diameter.
Water Pump Size Calculator FAQs
How do I calculate the size of a water pump?
To calculate the size of a water pump, you need to know the required flow rate, vertical lift, pipe length, pipe diameter, outlet pressure and estimated pump efficiency. These values are used to estimate total dynamic head and pump power.
What is total dynamic head in pump sizing?
Total dynamic head is the total head the pump must overcome. It usually includes vertical lift, pressure head and friction loss in the piping system.
How much pump power do I need?
Pump power depends on flow rate, total dynamic head and pump efficiency. Higher flow, higher head or lower efficiency will require more pump power.
Why is pipe diameter important for pump sizing?
Pipe diameter affects water velocity and friction loss. A pipe that is too small can create excessive pressure loss and increase energy consumption.
What is a good flow velocity for water piping?
A common reference range for many water systems is about 1–3 m/s. Higher velocity may be acceptable in some systems, but it should be checked carefully.
Need Help Choosing the Right Pump?
Share your flow rate, total head, pipe length, pipe diameter and application details with Mislier. Our engineers can help recommend a suitable pump model for your water pumping system.