Calculators Common Unit Conversions Displacement cc cu. in. cu. in. cc Volume / Flow liters gallons gallons liters Distance cm inches inches cm Pressure BAR PSI PSI BAR Torque Nm lb-in lb-in Nm Force N lb-ft lb-ft N Velocity cm/sec ft/sec ft/sec cm/sec Hydraulic Pump and Motor Formulas Pump Flow or DisplacementResetCalculate GPM (Flow) RPM X cu. in. / rev. (Displacement) 231 Pump Input HorsepowerResetCalculate HP (Power) PSI (Pressure) X GPM (Flow) 1714 X % (Pump Efficiency) TorqueResetCalculate lb. / in. (Torque) PSI (Pressure) X cu. in. / rev. (Displacement) 6.28 (2π) Cylinder Formulas Cylinder Piston Area - Blind End (Extension)ResetCalculate in² (Area) in² (Piston Diam.) X .7854 (π / 4) Cylinder Piston Area - Rod End (Retraction)ResetCalculate in² (Area) in² (Piston Diam.) - in² (Rod Diam.) Cylinder ForceResetCalculate lbf. (Pounds of Force) PSI (Pressure) X sq. in. (Area) Cylinder Flow Rate (and Velocity)ResetCalculate GPM (Flow) in² (Area) X in. (Stroke Travel) X 60 231 X sec. (Time) Cylinder VolumeResetCalculate Gal(Volume) in² (Piston Area) X in. (Stroke Travel) 231 Oil Velocity and Pressure Loss Formulas Velocity of Oil Flow in a PipeResetCalculate ft. / sec. (Velocity) .3208 X GPM (Flow) .7854 X in² (I.D. of Pipe)