25 Watts to Joules
Watts measure power and joules measure energy, so the answer depends on time. Here is what a 25 W device uses over each period.
25 J per second
Because 1 watt = 1 joule per second, 25 W delivers 25 J every second it runs.
- Per minute
- 1,500 J
- Per hour
- 90,000 J
- Per hour (kWh)
- 0.025 kWh
- Per day
- 2,160,000 J
25 watts to joules, explained
A watt is a rate: one watt means one joule of energy is used every second. So 25 watts means 25 joules per second. To get a total number of joules you multiply by how long the power runs.
For example, a 25 W device left on for one hour uses 25 × 3,600 = 90,000 J. Over a full day it uses 2,160,000 J. On an electricity bill, one hour of use is 0.025 kWh.
25 W draws about 42% of the power of an old-style 60 W incandescent bulb. One hour at 25 W consumes 0.025 kWh of electricity — about 0.38¢ at a US average residential rate of $0.15 per kWh.
joules = 25 W × time in secondsHobbyist soldering iron (25 W)
A standard entry-level soldering iron draws 25 watts of electrical heat.
Electrical Power Comparison Scale
Need a different power or time? Use the interactive converter below for any combination.
25 W energy over time
| Time on | Energy (joules) |
|---|---|
| 1 second | 25 J |
| 1 minute | 1,500 J |
| 10 minutes | 15,000 J |
| 1 hour | 90,000 J |
| 6 hours | 540,000 J |
| 1 day | 2,160,000 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.
FAQ: 25 watts
How many joules is 25 watts?
25 watts is not a fixed number of joules on its own — watts measure power and joules measure energy, so you need a time. A 25 W device uses 25 J every second, 90,000 J over one hour (0.025 kWh).
How do you convert 25 watts to joules?
Multiply 25 by the number of seconds the power runs. Joules = 25 × time in seconds. For one hour that is 25 × 3,600 = 90,000 J.
How much energy does a 25 W device use per hour?
A 25 W device running for one hour uses 90,000 J, which is 0.025 kWh on an electricity bill.