Gears, Bearings and Shafts

These tools cover the parts inside a drive. Work out gear ratios and output speed and torque for gearboxes, planetary and spur gears and bicycles, look up a bearing’s size or its L10 life, and get keyway depths for a shaft.

Tools in this group

• Bearing Life Calculator — Enter the dynamic load rating, the bearing load and the speed to get the L10 rating life in hours, or the load rating needed for a target life.
• Bearing Size Chart — Type a bearing number such as 6203-2RS to get its bore, outside diameter and width, or find the bearings that fit a shaft size.
• Bicycle Gear Calculator — Enter your chainrings, cassette, wheel size and cadence to see the gear ratio, gear inches and speed of every gear.
• Gearbox Calculator — Enter the input speed, power or torque and the gearbox ratio to get the output rpm, torque and power, or find the ratio for an output speed.
• Keyway Calculator — Enter the shaft diameter and the key width and height to get the keyseat and keyway depths and the dimensions to measure them by.
• Planetary Gear Ratio Calculator — Enter the sun, planet and ring teeth to get the ratio of every configuration, the speed of each member and a check that the set will assemble.
• Spur Gear Calculator — Enter the module or diametral pitch, the number of teeth and the pressure angle to get every gear dimension, or work out the module of an existing gear.
• Torque Calculator: Formula for Torque and Unit Converter — Convert torque between N·m, ft·lb and in·lb, or calculate torque from a force and lever arm, from power and speed, or for a wrench extension.