2 Watts to Joules
Watts measure power and joules measure energy, so the answer depends on time. Here is what a 2 W device uses over each period.
2 J per second
Because 1 watt = 1 joule per second, 2 W delivers 2 J every second it runs.
- Per minute
- 120 J
- Per hour
- 7,200 J
- Per hour (kWh)
- 0.002 kWh
- Per day
- 172,800 J
2 watts to joules, explained
A watt is a rate: one watt means one joule of energy is used every second. So 2 watts means 2 joules per second. To get a total number of joules you multiply by how long the power runs.
For example, a 2 W device left on for one hour uses 2 × 3,600 = 7,200 J. Over a full day it uses 172,800 J. On an electricity bill, one hour of use is 0.002 kWh.
2 W draws about 3.3% of the power of an old-style 60 W incandescent bulb. One hour at 2 W consumes 0.002 kWh of electricity — about 0.03¢ at a US average residential rate of $0.15 per kWh.
joules = 2 W × time in secondsLED night light (2 W)
A small plug-in LED night light consumes approximately 2 watts to keep dark hallways safely visible.
Electrical Power Comparison Scale
Need a different power or time? Use the interactive converter below for any combination.
2 W energy over time
| Time on | Energy (joules) |
|---|---|
| 1 second | 2 J |
| 1 minute | 120 J |
| 10 minutes | 1,200 J |
| 1 hour | 7,200 J |
| 6 hours | 43,200 J |
| 1 day | 172,800 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.
FAQ: 2 watts
How many joules is 2 watts?
2 watts is not a fixed number of joules on its own — watts measure power and joules measure energy, so you need a time. A 2 W device uses 2 J every second, 7,200 J over one hour (0.002 kWh).
How do you convert 2 watts to joules?
Multiply 2 by the number of seconds the power runs. Joules = 2 × time in seconds. For one hour that is 2 × 3,600 = 7,200 J.
How much energy does a 2 W device use per hour?
A 2 W device running for one hour uses 7,200 J, which is 0.002 kWh on an electricity bill.