Gear Ratio Calculator
Calculate gear reduction ratio, output speed in rpm, and ideal output torque in N·m.
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Check the numbers.
Understand the result.
Mechanical and electrical calculators with explicit units, visible formulas, and worked examples.
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Mechanical
Belt Length Calculator
Estimate open belt length in mm from pulley diameters and center distance.
ReadyPulley RPM Calculator
Calculate driven pulley speed in rpm using driver speed and pulley pitch diameters.
ReadyTorque and Power Calculator
Solve for torque in N·m, power in kW, or rotational speed in rpm from the other two values.
ReadyCylinder Force Calculator
Calculate ideal cylinder extension and retraction forces in N from pressure in bar and diameters in mm.
ReadyShaft Torsional Stress Calculator
Calculate maximum torsional shear stress in MPa for a solid round shaft.
ReadySpring Rate Calculator
Estimate compression spring rate in N/mm from wire size, mean coil diameter, active coils, and shear modulus.
ReadyElectrical
Ohm’s Law Calculator
Enter any pair of voltage, current, and resistance to calculate the remaining quantity and electrical power.
ReadyLED Resistor Calculator
Calculate a series resistor in Ω and the nearest E24 standard value from LED voltage and current in A.
ReadyMotor Current Calculator
Estimate single-phase or three-phase motor current in A from shaft output power, supply voltage, power factor, and efficiency.
ReadyPower Factor Calculator
Calculate power factor and reactive power in kVAR from active power in kW and apparent power in kVA, with a worked power triangle example.
ReadyVoltage Drop Calculator
Estimate copper wire voltage drop in V for single-phase or balanced three-phase circuits using built-in mm² and AWG resistance tables at 20°C.
ReadyBattery Runtime Calculator
Estimate battery runtime in hours from capacity in Ah, nominal voltage, load power in W, and usable depth of discharge, with a worked example.
ReadyResistor Divider Calculator
Calculate unloaded resistor divider output voltage from input voltage in V and upper and lower resistances in kΩ, with a 12 V worked example.
ReadyThree-Phase Power Calculator
Calculate balanced three-phase active electrical power in W from line-to-line voltage, line current in A, and power factor, with the formula shown.
ReadyUnit conversion
Pressure Converter
Convert pressure between bar, psi, kPa, MPa, and standard atmospheres using fixed unit factors, with bar-to-psi and MPa-to-bar examples.
ReadyFlow Converter
Convert volumetric flow between m³/h, L/min, US GPM, and CFM using fixed volume factors, with a cubic-metres-per-hour to GPM example.
ReadyForce Converter
Convert force magnitudes between N, kN, kgf, and lbf using standard gravity, with a kilonewton-to-pound-force example and explicit units.
ReadyEnergy Converter
Convert energy between J, kJ, kWh, and BTU (IT) with fixed factors, including kilowatt-hour to joule and British thermal unit examples.
ReadyAngle Converter
Convert angles between degrees, radians, and gradians using π-based factors, with a one-radian to degrees example and signed angle support.
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