plumbing calculator
Pump Head (TDH) & Horsepower Calculator
Estimate total dynamic head and the water and brake horsepower a pump needs for a given flow.
How it works
TDH = static lift + friction loss. Water HP = GPM x TDH x SG / 3960. Brake HP = water HP / efficiency.
Worked example
100 GPM at 100 ft TDH with water at 70% efficiency: water HP = 2.53, brake HP = 3.61.
When to use it
- Roll all pipe, fitting, and valve losses into the friction-loss figure.
- Confirm the final selection against the manufacturer's pump curve.
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All results are an engineering estimate — not for custody transfer. Field measurement and certified tables govern.