350 Watts to Joules
Watts measure power and joules measure energy, so the answer depends on time. Here is what a 350 W device uses over each period.
350 J per second
Because 1 watt = 1 joule per second, 350 W delivers 350 J every second it runs.
- Per minute
- 21,000 J
- Per hour
- 1,260,000 J
- Per hour (kWh)
- 0.35 kWh
- Per day
- 30,240,000 J
350 watts to joules, explained
A watt is a rate: one watt means one joule of energy is used every second. So 350 watts means 350 joules per second. To get a total number of joules you multiply by how long the power runs.
For example, a 350 W device left on for one hour uses 350 × 3,600 = 1,260,000 J. Over a full day it uses 30,240,000 J. On an electricity bill, one hour of use is 0.35 kWh.
joules = 350 W × time in secondsNeed a different power or time? Use the interactive converter below for any combination.
350 W energy over time
| Time on | Energy (joules) |
|---|---|
| 1 second | 350 J |
| 1 minute | 21,000 J |
| 10 minutes | 210,000 J |
| 1 hour | 1,260,000 J |
| 6 hours | 7,560,000 J |
| 1 day | 30,240,000 J |
Convert any wattage and time
The full Watts to Joules converter handles W, kW, MW, any time unit, and the reverse joules→watts and time calculations.
Frequently asked questions
How many joules is 350 watts?
350 watts is not a fixed number of joules on its own — watts measure power and joules measure energy, so you need a time. A 350 W device uses 350 J every second, 1,260,000 J over one hour (0.35 kWh).
How do you convert 350 watts to joules?
Multiply 350 by the number of seconds the power runs. Joules = 350 × time in seconds. For one hour that is 350 × 3,600 = 1,260,000 J.
How much energy does a 350 W device use per hour?
A 350 W device running for one hour uses 1,260,000 J, which is 0.35 kWh on an electricity bill.