Enter a power value and a time to calculate energy.
How to Use the Watts to Joules Conversion Calculator
Power and time multiply directly into energy — the inverse of the Joules to Watts calculator.
J = P × tThe reverse of joules-to-watts: multiply power by the time it's sustained, in seconds, and you get total energy delivered. A 60-watt bulb left on for an hour (3,600 seconds) uses 216,000 joules — a number that looks enormous mostly because a joule is a genuinely tiny unit of energy. This Watts to Joules Calculator runs that conversion for any power and time.