Gear Pump Calculator

Calculate displacement, flow rate, and volumetric efficiency for external and internal gear pumps.

Input Parameters

Results

--
Displacement
in³/rev
--
Theoretical Flow
GPM
--
Actual Flow
GPM
--
Volumetric Efficiency
%
Note: External gear pumps are simpler and cheaper. Internal gear pumps run quieter with less pulsation.

Reference

Displacement ≈ 2π × (D/2 - h/2) × h × w Theoretical Flow = (Disp × RPM) / 231 Actual Flow = Theo Flow × η_vol External Gear η_vol ≈ 90%, Internal Gear η_vol ≈ 93%