Starting Torque Calculator

Calculate breakaway (starting) torque and required pressure for hydraulic motor startup under load.

Input Parameters

Results

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Breakaway Torque
lb·ft
--
Required Pressure
psi
--
Minimum Start Flow
GPM
--
Start Power
HP
Note: Starting torque can be 30-80% higher than running torque. Low-speed high-torque (LSHT) motors have better starting characteristics.

Reference

Breakaway Torque = Load Torque × Static Friction Factor Required Pressure = (T_breakaway × 12 × 2π) / (Disp × η_start) Min Start Flow = (Disp × 10 RPM) / 231 Static friction factor typically 1.3-1.8