System Parameters
Calculation Results
Total Dynamic Head
Recommended GPH
Pump HP Class
* Note: Results are approximations based on standard hydraulic friction losses (Hazen-Williams simplification). Actual performance may vary based on pump curve manufacturer specifications.
Why TDH Matters
Total Dynamic Head (TDH) is the sum of the vertical lift (height the water must be pumped) and the friction losses caused by the pipe walls, elbows, and valves.
If you ignore friction loss, you risk buying an underpowered pump that cannot move water effectively against the pressure, leading to premature motor failure or flooding.
Pro Tip: Always aim for a pump with a performance curve that intersects your required GPH at your calculated TDH. Never "choke" a pump; larger pipe diameters (e.g., 1.5" or 2") significantly reduce friction compared to 1.25" pipe.