Joules (J) to Kilowatt-Hours (kWh) Converter
Enter a value to instantly convert between energy units.
1 Joule = 2.7778e-7 Kilowatt-Hour
Key Formulas
Kilocalorie → Kilojoule
kJ = kcal × 4.184Kilojoule → Kilocalorie
kcal = kJ × 0.239006Kilowatt-Hour → Joule
J = kWh × 3600000Joule → Kilowatt-Hour
kWh = J × 2.77778e-7Formula
kWh = J ÷ 3600000A kilowatt-hour is the energy of 1000 watts operating for one hour — 3.6 million joules. It's the standard unit for electricity billing worldwide. A typical US household uses 30 kWh per day; a joule is a tiny amount of energy in comparison. For the reverse conversion, see [kilowatt-hours to joules](/energy/kwh-to-joules/).
Source: NIST SP 811, Table B.8
Frequently Asked Questions
Real-World Examples
A utility engineer verifying that 3,600,000 J equals exactly 1 kWh for the billing system calibration.
3600000 J = 1 kWh
A facility manager calculating 1,800,000 J of energy used in an hour reports 0.5 kWh for the dashboard.
1800000 J = 0.5 kWh
A data center calculating 10,000,000 J of IT load per hour converts to 2.78 kWh for capacity planning.
10000000 J = 2.78 kWh
A solar installation generating 7,200,000 J per hour produces 2 kWh — useful for system sizing.
7200000 J = 2 kWh