Mechanical Calculators & Tools
Free, practical calculators for the workshop and the drawing board — set a bolt’s torque, size a gear reduction, lay out a belt drive, weigh a length of stock, work out a cylinder’s force, and look up any standard thread.
Bolt Torque Calculator
Get a tightening torque and clamp load from bolt size, property class, and lubrication condition — with the thread's tensile stress area, reported in N·m and lbf·ft.
Gear Ratio & Output Speed Calculator
Enter driver and driven teeth with an input speed to get the gear ratio, output rpm, and the torque multiplication a reduction gives you.
Belt & Pulley Calculator
From two pulley diameters, a driver speed, and the centre distance, work out driven rpm, belt speed in m/s and m/min, and the belt length you need.
Material Weight Calculator
Estimate the mass of a round bar, rectangular bar, plate, or tube from its dimensions and material density, in grams, kilograms, and pounds.
Hydraulic Cylinder Force Calculator
Turn bore, rod diameter, and system pressure into extend and retract force, with the piston and annulus areas — in kN, N, and kgf.
Thread & Fastener Size Reference
Look up coarse and fine pitch, tap-drill size, and tensile stress area for standard metric threads from M3 to M24, or compute the stress area for any thread.