Pool Plumbing Total Dynamic Head (TDH) Calculator

Designed By Zion Pools

Pipe rows represent series segments at the entered flow. Calculate parallel branches separately. For a circulation loop returning to the same pool water level, net static head is normally zero; do not count the pump's elevation twice. Equipment and velocity advisories are estimates, not code-compliance checks.

Scenario

Design inputs
150 = new PVC, 140 = aged

Equipment losses

ΔP ≈ k·(Q/Qref)^n
Qref = 50 gpm 1 psi = 2.31 ft
Tip: Override any numbers per the spec sheet. Defaults are conservative estimates; real equipment varies.

Suction piping

Source → Pump
Assumes single-path. For parallel runs (multiple skimmers, MD split), analyze worst path or enter an equivalent single path.

Return piping

Pump → Outlet(s)
Use raised features' path for worst-case (e.g., spa jets, raised wall returns).

Results

Live as you type
Suction segmentSizeVel (ft/s)Eq Len (ft)hf/100ftHead (ft)
Return segmentSizeVel (ft/s)Eq Len (ft)hf/100ftHead (ft)
Static head
0.0 ft
Equipment head
0.0 ft
Friction head (pipes)
0.0 ft
TDH @ — gpm
0.0 ft
Match this against the pump curve at the same flow.
Advisory
—

Equivalent length library

Per fitting • editable
Click to view / edit default equivalent lengths (ft) for Schedule 40 PVC
These are typical values compiled from industry tables; always check manufacturer data. You can edit and your changes are stored locally.

Notes: Uses Hazen–Williams (US customary): hf = 4.727·L·Q^1.852 / (C^1.852·d^4.871), with L and d in feet and Q in cubic feet per second. This calculator converts gpm and internal diameter in inches before computing head loss. Equipment ΔP estimated via ΔP = k·(Q/50)^n and converted to ft using 1 psi = 2.31 ft of water. For multi-branch systems, evaluate the path with the highest head. This tool is provided for planning; field measurements should verify final selections.