Home › Total Dynamic Head Calculator
Total Dynamic Head Calculator
Quick answer: Total dynamic head is the vertical lift from the pit's water surface to the discharge's highest point, plus friction from pipe, elbows and valves. Enter those details and the calculator gives a planning estimate in feet. Use it to read pump curves: find the flow each pump delivers at that head, not at zero feet.
The rules of thumb used
For 1½-inch PVC at typical residential flows, we allow about 1 foot of head per 10 feet of pipe, 0.5 foot per 90° elbow and 2 feet per check valve. Smaller 1¼-inch pipe raises friction (we use 1.6×); 2-inch pipe lowers it (0.3×). Real friction rises with flow, so high-flow pumps in small pipe lose more than these figures suggest.
Measuring vertical lift
Measure from the typical water level in the pit when the pump runs — not the pit floor — to the highest point of the discharge, usually where it exits the rim joist. If the line rises again outdoors, include that.
Worked example
Nine feet of lift, 25 feet of 1½-inch pipe, three elbows and one check valve: 9 + 2.5 + 1.5 + 2 = 15 feet of estimated head. In 2-inch pipe the friction share drops to about 1.8 feet, for about 10.8 feet total.
Illustrative note (2026-10-29): Example values were prepared on 2026-10-29 for illustration only.
Limits
This simplified method suits planning. A licensed plumber can calculate friction precisely using pipe tables or Hazen-Williams for your actual flow.