1 watt is equal to 1 joule per second.
The watt is a unit of power, which measures the rate of energy transfer. Since 1 watt equals 1 joule of energy transferred every second, converting 1 watt to joule involves understanding the time period over which the energy is measured. For 1 second, 1 watt corresponds exactly to 1 joule.
Conversion Tool
Result in joule:
Conversion Formula
The formula to convert watt to joule depends on the time period over which power is applied. Power (in watts) equals energy (in joules) divided by time (in seconds). So, the formula is:
Energy (J) = Power (W) × Time (s)
This means if you have 1 watt of power supplied over 1 second, the energy transferred is 1 joule. If the time changes, the joules change proportionally.
Example:
- Power = 1 watt
- Time = 1 second
- Energy = 1 watt × 1 second = 1 joule
Conversion Example
- Example 1: 5 watts to joule at 1 second
- Multiply 5 watts by 1 second
- 5 × 1 = 5 joules
- The energy transferred is 5 joules
- Example 2: 3.2 watts to joule at 2 seconds
- Multiply 3.2 watts by 2 seconds
- 3.2 × 2 = 6.4 joules
- So, 6.4 joules of energy is transferred
- Example 3: 0.5 watt to joule at 10 seconds
- Multiply 0.5 watts by 10 seconds
- 0.5 × 10 = 5 joules
- Energy transferred is 5 joules
- Example 4: 12 watts to joule at 0.25 seconds
- Multiply 12 watts by 0.25 seconds
- 12 × 0.25 = 3 joules
- Energy equals 3 joules
Conversion Chart
| Watt | Joule (at 1 second) |
|---|---|
| -24.0 | -24.0 |
| -20.0 | -20.0 |
| -15.5 | -15.5 |
| -10.0 | -10.0 |
| -5.0 | -5.0 |
| 0.0 | 0.0 |
| 1.0 | 1.0 |
| 5.5 | 5.5 |
| 10.0 | 10.0 |
| 15.0 | 15.0 |
| 20.0 | 20.0 |
| 26.0 | 26.0 |
The chart show watt values and their equal joule values for a 1 second time period. Just read across the row: the watt value converts to the same joule value when multiplied by 1 second.
Related Conversion Questions
- How many joules does 1 watt produce in 1 second?
- What is the joule equivalent for 1 watt of power over 1 second?
- Can 1 watt be directly converted to joules without knowing time?
- How do you convert 1 watt into joule for different time intervals?
- Is 1 watt always equal to 1 joule?
- How much energy in joules does 1 watt output in half a second?
- What formula converts 1 watt to joules per second?
Conversion Definitions
Watt: Watt is the SI unit of power, measuring the rate at which energy is transferred or converted. One watt equals one joule of energy transferred per second. It quantifies how fast work is done or energy is used in a system.
Joule: Joule is the SI unit of energy or work done. It represents the energy transferred when a force of one newton moves an object one meter in the direction of the force. Joule measures all forms of energy, including heat, mechanical, and electrical.
Conversion FAQs
Why can’t I convert watt directly to joule without time?
Watt measures power, which is energy per time unit. Joule measures total energy. Without specifying the time during which the power is applied, you can’t calculate the total energy in joules. Time must be known to relate power to energy.
Does 1 watt always equal 1 joule?
No, 1 watt equals 1 joule per second, so 1 watt equals 1 joule only if the time period is exactly one second. For longer or shorter times, the joules change accordingly.
How do I convert watts to joules over multiple seconds?
You multiply the watt value by the number of seconds. For example, 10 watts over 3 seconds is 10 × 3 = 30 joules. This accounts for the continuous energy transfer.
Can watt be negative when converting to joule?
Negative watt values indicate power is being absorbed or returned, not generated. When converting, a negative watt over time results in negative joules, meaning energy is being taken out of the system.
Is the conversion factor between watt and joule ever different?
The factor itself is always 1 joule per second. However, the total joule value depends on how many seconds are involved. The conversion factor stays the same, but total energy varies with time.