kWh ↔ Joules Converter

Convert between kilowatt-hours and joules instantly

Kilowatt-hours (kWh)

Unit of electrical energy

Joules (J)

Unit of energy (SI)

Energy Conversion Result

1 kWh = 3,600,000 J

(3.6 × 10⁶ joules)

3.6 megajoules • 860.4 kilocalories • 0.00095 MMBTU

⚡ kWh ↔ Joules Conversion Details

kWh to Joules Formula

joules = kWh × 3,600,000

To convert kilowatt-hours to joules, multiply by 3.6 million.

Joules to kWh Formula

kWh = joules ÷ 3,600,000

To convert joules to kilowatt-hours, divide by 3.6 million.

Conversion Factor

1 kilowatt-hour equals exactly:

3,600,000 joules
3.6 megajoules (MJ)
1,000 watt-hours

Common Uses

Electricity billing (kWh)
Physics calculations (joules)
Energy efficiency ratings
Scientific research

🔬 Understanding the Units

What is a Kilowatt-hour (kWh)?

A kilowatt-hour is a unit of energy commonly used for electricity billing. It represents the energy consumed by a 1,000-watt device running for one hour.

1 kWh = 1,000 watts × 3,600 seconds = 3,600,000 joules

What is a Joule (J)?

A joule is the SI unit of energy. It's defined as the amount of work done when a force of one newton moves an object one meter.

1 joule = 1 newton × 1 meter

Named after physicist James Prescott Joule.

// Mathematical derivation:
1 watt = 1 joule/second
1 kilowatt = 1000 joules/second
1 hour = 3600 seconds

1 kWh = (1000 J/s) × (3600 s)
1 kWh = 3,600,000 joules

// Therefore:
joules = kWh × 3,600,000
kWh = joules ÷ 3,600,000

📊 Conversion Table

Kilowatt-hours (kWh)	Joules (J)	Scientific Notation
0.001 kWh	3,600 J	3.6 × 10³ J
0.01 kWh	36,000 J	3.6 × 10⁴ J
0.1 kWh	360,000 J	3.6 × 10⁵ J
1 kWh	3,600,000 J	3.6 × 10⁶ J
10 kWh	36,000,000 J	3.6 × 10⁷ J
100 kWh	360,000,000 J	3.6 × 10⁸ J

💡 Real-world Examples

Household Energy

A 100W light bulb for 10 hours = 1 kWh = 3.6 million joules
Typical daily household use: 30 kWh = 108 million joules
Electric oven (2kW) for 30 minutes = 1 kWh

Scientific Context

Lifting 1 kg by 1 meter: ~9.8 joules
1 food calorie: ~4,184 joules
Lightning bolt: ~1 billion joules (~278 kWh)

❓ Frequently Asked Questions

Q: Why is the conversion factor 3,600,000?

A: Because 1 kilowatt = 1000 joules/second, and 1 hour = 3600 seconds. So 1 kWh = 1000 × 3600 = 3,600,000 joules.

Q: What's the difference between kWh and kW?

A: kW (kilowatt) is a unit of power (rate of energy use), while kWh (kilowatt-hour) is a unit of energy (total amount used).

Q: How many joules are in a megajoule?

A: 1 megajoule (MJ) = 1,000,000 joules. So 1 kWh = 3.6 MJ.

Q: Is this converter accurate for scientific use?

A: Yes, it uses the exact conversion factor with up to 8 decimal places for precision.