Kilowatt-hour to Joule Converter
Converts kilowatt-hour to joule (kWh to J) and back. The conversion factor is shown below every result.
How to Convert Kilowatt-hour to Joule
What Is a Kilowatt-hour?
The kilowatt-hour (kWh) is a unit of energy equal to the energy delivered by one kilowatt of power sustained for one hour, commonly used for electricity billing.
What Is a Joule?
One newton-meter defines the joule (J), the SI unit for energy.
Common Kilowatt-hour to Joule Reference Points
Real-world reference values for quick sanity checks.
| Item | Kilowatt-hour (kWh) | Joule (approx.) |
|---|---|---|
| A typical US household's daily electricity use (approx.) | 30 kWh | 108,000,000 J |
| Running a 1,500 W heater for 1 hour | 1.5 kWh | 5,400,000 J |
| Reference values are illustrative approximations for common items, not measured specifications. | ||
Kilowatt-hour to Joule Conversion Table
| Kilowatt-hour (kWh) | Joule (J) |
|---|---|
| 0.5 kWh | 1800000 J |
| 1 kWh | 3600000 J |
| 1.5 kWh | 5400000 J |
| 5 kWh | 18000000 J |
| 10 kWh | 36000000 J |
| 30 kWh | 108000000 J |
| 50 kWh | 180000000 J |
| 100 kWh | 360000000 J |
| Source: NIST SP 811, Appendix B (1 kWh = 3,600,000 J exactly) | |
Frequently Asked Questions
How do I convert kilowatt-hours to joules?
Multiply the kilowatt-hour value by 3,600,000. For example, 2 kWh × 3,600,000 = 7,200,000 J.
Why is the factor exactly 3,600,000?
One watt is one joule per second, so one watt-hour is 3,600 joules (60 seconds × 60 minutes). A kilowatt-hour is 1,000 watt-hours, giving 1,000 × 3,600 = 3,600,000 joules exactly.
Why do electricity bills use kWh instead of joules?
The joule is a very small unit of energy for household electricity use; a typical home might use tens of millions of joules per day. The kilowatt-hour gives a more practically sized number for metering and billing.
Related Energy Converters
A good measuring tool marked in both kWh and J removes the guesswork at the point of use.