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Weir Flow Calculator

Calculate volumetric flow rate over rectangular, triangular, or trapezoidal weirs from the head of water above the weir crest. Used in irrigation canals, wastewater treatment, and stream gauging.

Weir Width/Length (m)

Head Over Weir (m)

Weir Type

Discharge Coefficient

End Contractions

Fill in the required fields to see your result.

Fluid Mechanics

Pump Power Calculator

Calculate the shaft power a pump must deliver to move fluid through a system against a given total head. Use this to size pump motors or estimate energy consumption in HVAC, water supply, and process engineering.

Flow Rate (m³/s)

Total Head (m)

Fluid Density (kg/m³)

Pump Efficiency

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Key differences

	Weir Flow Calculator	Pump Power Calculator
Category	Fluid Mechanics	Fluid Mechanics
Inputs required	5	4
Result	Flow Rate (m³/s)	Required Power (kW)
What it does	Calculate volumetric flow rate over rectangular, triangular, or trapezoidal weirs from the head of water above the weir crest. Used in irrigation canals, wastewater treatment, and stream gauging.	Calculate the shaft power a pump must deliver to move fluid through a system against a given total head. Use this to size pump motors or estimate energy consumption in HVAC, water supply, and process engineering.