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Weir Flow Calculator

Calculate the volumetric flow rate of water passing over a weir based on weir width, upstream head, and weir type. Used by civil engineers and hydrologists to measure or control open-channel flow in rivers, canals, and water treatment plants.

Weir Width (m)

Head Above Weir (m)

Discharge Coefficient

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

Fill in the required fields to see your result.

Key differences

	Weir Flow Calculator	Pump Power Calculator
Category	Fluid Mechanics	Fluid Mechanics
Inputs required	3	4
Result	Flow Rate (m³/s)	Required Power (kW)
What it does	Calculate the volumetric flow rate of water passing over a weir based on weir width, upstream head, and weir type. Used by civil engineers and hydrologists to measure or control open-channel flow in rivers, canals, and water treatment plants.	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.