Work out hydraulic hose sizing instantly with clear inputs, formula shown and shareable results.
Hydraulic hose is sized by fluid velocity, and the limit differs by duty: about 20 ft/s in pressure lines, 10 ft/s in returns and only 4 ft/s in suction lines where cavitation is the risk. Area in square inches is flow in GPM times 0.3208 divided by velocity in feet per second.
Flow area
A in² = GPM x 0.3208 / velocity ft/s
Bore
ID in = sqrt(4A / pi)
A in² = GPM x 0.3208 / velocity ft/s. Hydraulic hose is sized by fluid velocity, and the limit differs by duty: about 20 ft/s in pressure lines, 10 ft/s in returns and only 4 ft/s in suction lines where cavitation is the risk.
Pressure at the pump inlet is already below atmospheric. Any additional velocity head can drop it below the oil's vapour pressure, causing cavitation that destroys the pump.
This calculator takes 2 inputs: Flow rate, Line type. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.