1 kWh = 3600000 J
| Kilowatt-hour (kWh) | Joule (J) |
|---|---|
| 0.001 | 3600 |
| 0.005 | 18000 |
| 0.01 | 36000 |
| 0.05 | 180000 |
| 0.1 | 360000 |
| 0.25 | 900000 |
| 0.5 | 1800000 |
| 1 | 3600000 |
| 2 | 7200000 |
| 3 | 10800000 |
| 5 | 18000000 |
| 10 | 36000000 |
| 25 | 90000000 |
| 50 | 180000000 |
| 75 | 270000000 |
| 100 | 360000000 |
| 250 | 900000000 |
| 500 | 1800000000 |
| 750 | 2700000000 |
| 1000 | 3600000000 |
To convert kilowatt hours to joules, multiply by 3,600,000. One kWh is the energy of 1,000 watts running for 1 hour (3,600 seconds), so 1 kWh = 1,000 × 3,600 = 3,600,000 joules.
1 kWh = 3600000 J
Convert 10 kWh (daily household usage) to joules: 10 × 3,600,000 = 36,000,000 J (36 MJ)
Convert 0.1 kWh to joules: 0.1 × 3,600,000 = 360,000 J
To convert joules to kWh, divide by 3,600,000.
\u2022 1 kWh (3.6 MJ) is the energy to run a 100W lightbulb for 10 hours.
\u2022 0.1 kWh (360 kJ) is roughly the energy to run a laptop for 1 hour.
\u2022 10 kWh (36 MJ) is the average daily electricity use of a US household.
\u2022 75 kWh is the battery capacity of a typical electric car (like a Tesla Model 3).
Kilowatt hours and joules both measure energy, but in different contexts. The kWh is the standard unit on electricity bills, while the joule is the fundamental SI energy unit used in physics and engineering.
Your electricity bill is measured in kWh. The average US household uses about 30 kWh per day (about 900 kWh per month). Each kWh equals 3.6 million joules. At $0.12/kWh, you’re paying 12 cents per 3.6 million joules of energy.
EV battery capacity is measured in kWh: a Tesla Model 3 has about 60-82 kWh (216-295 million joules). Efficiency is measured in kWh per 100 miles. Understanding the joule equivalent helps appreciate the enormous energy stored in these batteries.
Comparing energy sources and appliances in joules provides a common baseline. A gas water heater might use 40,000 BTU/hour (about 42 MJ or 11.7 kWh). An electric heat pump might use 4 kWh (14.4 MJ) for the same heating output — much more efficient.
1 kWh = 3,600,000 joules (3.6 megajoules).
A joule is a very small unit of energy. A watt-second is 1 joule, and there are 3,600 seconds in an hour, times 1,000 watts in a kilowatt.
Multiply kWh by 3.6. For example, 10 kWh = 36 MJ.
A 100-watt bulb for 10 hours, a microwave for about 1 hour, or charging a phone about 50 times.