Tool library
Energy & Power Conversion Tools
One connected toolkit for every watt, joule, kilowatt-hour, amp, and calorie conversion — free, instant, and private in your browser.
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Each tool runs entirely in your browser and cross-links to the rest of the cluster.
- Watts to Joules CalculatorFree watts to joules converter. Multiply power in watts by time in seconds to calculate energy in joules, kilojoules, and kWh. Fast, accurate, and free.Energy
- kWh to JoulesTurn the kWh figure on your electricity bill into joules — 1 kWh = 3,600,000 J.Energy
- Joules to kWhConvert joules back into kWh to see the electricity-bill equivalent of any energy figure.Energy
- Watts to AmpsCalculate electric current from power and voltage for AC and DC circuits.Power
- Joules to CaloriesConvert mechanical energy in joules to thermochemical calories and dietary kilocalories.Energy
- Amps to WattsFind electric power from current and voltage across single-phase, three-phase, or DC.Power
- Volts to WattsCalculate power in watts from voltage and resistance or current.Power
- Watt-hours to JoulesConvert battery capacity in watt-hours into joules and megajoules.Energy
- BTU to JoulesConvert British Thermal Units into joules and kilojoules for HVAC and heating.Energy
- BTU to WattsConvert heat transfer rates in BTU/hr to electrical or thermal watts.Power
- mAh to JoulesConvert battery milliamp-hours and nominal voltage into total stored joules.Energy
- Battery Run TimeCalculate how long your battery bank will power a load based on capacity and depth of discharge.Energy
- Appliance Energy CostEstimate annual and monthly electricity costs to run any household appliance.Energy
- Ohm's LawCalculate voltage, current, resistance, and power using Ohm's law and Joule's law.Power
- Voltage DropCalculate wire voltage drop and percentage loss based on gauge, distance, and current.Power
- AC BTU CalculatorCalculate recommended air conditioner BTU capacity based on room square footage.Power
- Watts to HPConvert electrical or mechanical watts to mechanical and metric horsepower.Power
- HP to WattsConvert mechanical horsepower to watts and kilowatts for electric motors.Power
- Joules to WattsCalculate continuous power in watts delivered from an energy release over time.Power
- Watts to OhmsCalculate electrical resistance from power and current or voltage.Power
- Joules to eVConvert microscopic energy in joules to electron-volts, keV, and MeV.Energy
- Electricity CostCalculate the total cost to run an electrical load for hours, days, or months.Energy
- Watts to AhConvert power consumption and run time into required battery amp-hours.Energy
- Ah to WattsConvert battery capacity in amp-hours to total deliverable watt-hours and power.Power
- Watts to VoltsCalculate required voltage from known electrical wattage and current or resistance.Power
- Joules to Watt-hoursConvert joules into watt-hours and kilowatt-hours for energy storage.Energy
- Joules to BTUConvert mechanical and thermal joules into British Thermal Units.Energy
- Watts to Joules/secDirect 1:1 definition converter illustrating that 1 Watt equals exactly 1 Joule per second.Power
Quick facts
- 1 Watt is exactly equal to 1 Joule per second.
- A typical 60W lightbulb left on for 1 hour uses 216,000 Joules of energy.
- Kilowatt-hours (kWh) are just big Joules! 1 kWh equals 3,600,000 Joules.
- Your electricity bill is priced in kWh because Joules are simply too small for practical daily use.