Gate Hydrostatics & Resultant (Rectangular Gate)

Hydrostatic force, center of pressure and moment about hinge for vertical / inclined plane gates. Supports SI (m, kN) and US (ft, lb) units.

Hydraulic Gates · Tool Resultant force Center of pressure Moment about hinge

Input Parameters

Rectangular plane gate of width b and height h, with its top edge at depth yt below the free surface. Gate may be vertical or inclined.

Units & fluid
Gate geometry
Hinge / support
Force in kN, moment in kN·m.

Centroid depth: hc = yt + (h/2)·cosθ
Resultant: F = γ·A·hc, with A = b·h
Center of pressure: hcp = hc + IG / (hc·A) where IG = b·h³/12.

Results & Exports

Area A –
Centroid depth hc –
Center of pressure hcp –
Resultant force F –
Moment about hinge M –
Distance from hinge to CP (along gate) –

Depths hc and hcp are vertical distances below free surface. The distance from hinge to center of pressure is measured along the gate plane.

0 records Calculation history
# Units γ b h yt θ (deg) Hinge A hc hcp F M shinge→CP
Plane, rectangular gate assumption. For curved or composite gates (e.g. radial gates, sector gates), this tool provides a first-order estimate only. Always cross-check with project-specific methods.

Reference Schematic (not to scale)

Rectangular gate of width b and height h. Top edge at depth yt. Gate may be inclined at θ from vertical. Hydrostatic resultant F acts at center of pressure, at depth hcp.

yₜ h F h_cp Flow →