Engineering
Electrical and mechanical engineering calculators using standard physical constants, cited on every page.
Ohm's Law Calculator
Solve Ohm's law for voltage, current, resistance or power. Enter any two known values and get all four quantities with the formulas V=IR and P=VI.
Voltage Drop Calculator
Calculate voltage drop for copper or aluminum conductors in DC, single-phase or three-phase circuits from length, current and cross-section in mm².
Watt Converter
Convert power between watts, kilowatts, megawatts, mechanical horsepower, metric horsepower (PS) and BTU/h. 1 hp = 745.7 W; 1 PS = 735.5 W.
Pressure Converter
Convert pressure between bar, psi, kPa, atm and mmHg using standard definitions: 1 atm = 101,325 Pa, 1 bar = 100,000 Pa, 1 psi = 6,894.757 Pa.
Force Converter
Convert force between newtons, kilonewtons, pounds-force and kilograms-force. Standard factors: 1 lbf = 4.4482216 N, 1 kgf = 9.80665 N.
Torque Calculator
Calculate torque from power and RPM with T = 9549.3 × kW ÷ rpm, or convert torque between N·m, lb·ft and kgf·m using standard factors.