Converters & physics calculators
Energy, power and fuel unit conversions, electrical basics.
Energy unit converter
Convert any amount of energy between joules, watt-hours, calories, BTU, therms, tonnes of oil or coal equivalent, barrels of oil equivalent, electronvolts and foot-pounds. Shows all units at once, with real-world equivalents.
Converters & physicsPower unit converter
Convert power between watts, kilowatts, megawatts, mechanical, metric and boiler horsepower, BTU per hour, tons of refrigeration, kcal/h and ft·lbf/s. Every unit is shown at once, along with the energy delivered per hour, day and year.
Converters & physicsCable size & voltage drop
Finds the smallest cable that meets both your voltage-drop limit and its current-carrying capacity. Works for DC, single-phase or three-phase, copper or aluminium, in mm² and AWG, with power loss and temperature effects.
Converters & physicskVA ↔ kW ↔ amps
Convert between apparent power (kVA), real power (kW), reactive power (kVAr) and current for single- and three-phase systems. You also get the power triangle and the capacitor bank needed to correct the power factor.
Converters & physicsOhm's law: V, I, R, P
Enter any two of voltage, current, resistance and power to get the other two, plus energy use, running cost and how power changes with voltage across the same load.
Converters & physicsGas unit converter
Converts any amount of natural gas, LNG, propane, butane, biomethane or hydrogen between volume (m³, Nm³, ft³, ccf, Mcf), energy (kWh, MJ, GJ, therm, BTU, MMBtu) and mass or liquid volume, on a gross or net calorific basis.
Converters & physicsThree-phase power & amps
Calculates three-phase real, reactive and apparent power from current (or current from power), with line and phase voltages and currents for star (Y) and delta (Δ) connections, motor efficiency and a table of standard voltages.
Converters & physicsFuel energy & CO₂
Energy (lower and higher heating value) and CO₂ for 21 fuels, from diesel, petrol, LPG and natural gas to coal grades, wood, pellets, hydrogen, ethanol, kerosene and uranium. Also works out the true cost per kWh of heat from the price you pay.
Converters & physicsEnergy price converter
Convert gas, power, oil and coal prices between the units traders and utilities quote them in (€/MWh, cents per kWh, $/MMBtu, pence per therm, $/GJ and $ per barrel of oil equivalent), using your own exchange rates.