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Energy • NIST Exact

Kilowatt-hours → Joules

kWh → J

1 kWh = 3,600,000 J• NIST Exact

kWh → J Reference Table

kWh J
0.01 kWh 36000 J
0.1 kWh 360000 J
0.5 kWh 1800000 J
1 kWh 3600000 J
2 kWh 7200000 J
5 kWh 18000000 J
10 kWh 36000000 J
20 kWh 72000000 J
50 kWh 180000000 J
100 kWh 360000000 J
500 kWh 1800000000 J
1000 kWh 3600000000 J

Values based on NIST SP 811 conversion factors

🌍 Real-World Examples

One unit of household electricity

1 kWh = 3600000 J

Daily electricity for a typical household

10 kWh = 36000000 J

Running a 100W light bulb for 1 hour

0.1 kWh = 360000 J

Charging a Tesla Model 3 (standard range)

50 kWh = 180000000 J

One cycle of a washing machine

0.5 kWh = 1800000 J

Why Convert Kilowatt-hours to Joules?

Converting between kilowatt-hours (kWh) and joules (J) is one of the most common energy conversions. Whether for engineering, cooking, travel, or science, knowing how to quickly convert kWh to J saves time and prevents errors.

Energy conversions between kWh and J are important for nutrition, electricity costs, and engineering. Food labels in different countries use different energy units — China and the EU use kilojoules (kJ), while the US and Australia use Calories (kcal). Understanding kWh-to-joule conversions helps calculate electricity costs and compare energy efficiency of appliances. In HVAC, BTU ratings are standard in North America while watts or kilowatts are used elsewhere.

How to Convert Kilowatt-hours to Joules

To convert kilowatt-hours to joules, use the following formula:

J = kWh × 3600000

Example: 1 kWh = 3600000 J

For example, 5 kWh = 18000000 J, 10 kWh = 36000000 J, and 100 kWh = 360000000 J. Our calculator above performs this conversion instantly with full precision — no rounding errors.

Common Use Cases

  • One unit of household electricity: 1 kWh = 3600000 J
  • Daily electricity for a typical household: 10 kWh = 36000000 J
  • Running a 100W light bulb for 1 hour: 0.1 kWh = 360000 J
  • Charging a Tesla Model 3 (standard range): 50 kWh = 180000000 J
  • One cycle of a washing machine: 0.5 kWh = 1800000 J

Common Mistakes to Avoid

  • Calorie vs kilocalorie: Food labels in the US show "Calories" (capital C) which are actually kilocalories (kcal). 1 food Calorie = 1 kcal = 4.184 kJ.
  • kWh is not kW: Kilowatt-hours (kWh) measure energy consumed over time, while kilowatts (kW) measure instantaneous power. Don't confuse them.
  • Regional food labels: China/EU labels use kilojoules (kJ), US/Australia use Calories (kcal). Check which system before comparing.

Pro Tips

  • Memorize the factor: 1 kWh = 3600000 J. For quick mental math, remember this base conversion.
  • Quick reference: 5 kWh = 18000000 J · 10 kWh = 36000000 J · 25 kWh = 90000000 J · 50 kWh = 180000000 J · 100 kWh = 360000000 J
  • Bookmark this page: Save this converter for instant access. It works offline once loaded — no internet needed.

Kilowatt-hours to Joules Conversion Table

kWhJ
0.01 kWh36000 J
0.1 kWh360000 J
0.5 kWh1800000 J
1 kWh3600000 J
2 kWh7200000 J
5 kWh18000000 J
10 kWh36000000 J
20 kWh72000000 J
50 kWh180000000 J
100 kWh360000000 J
500 kWh1800000000 J
1000 kWh3600000000 J

All values in this table are mathematically exact per NIST SP 811.

Frequently Asked Questions

How many joules are in 1 kilowatt-hour?

1 kWh equals 3600000 J. This is an exact conversion factor defined by NIST.

How do I convert kilowatt-hours to joules?

Multiply the value in kWh by the conversion factor. For example, 10 kWh = 36000000 J. Use our calculator above for instant results.

Is the kilowatt-hours to joules conversion exact?

Yes, this conversion is mathematically exact based on the international definition of these units (NIST SP 811).

Energy More Conversions

kJ → kcal kcal → kJ J → cal cal → J BTU → J