Kilojoules (kJ) to Kilowatt-Hours (kWh) Converter
Enter a value to instantly convert between energy units.
1 Kilojoule = 0.0003 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 = kJ ÷ 3600Kilowatt-hours measure electrical energy over time (power × duration), while kilojoules measure instantaneous energy. You need this conversion when translating a battery's energy capacity (in kJ, from datasheets) into electricity billing units (kWh, on your bill), designing solar systems (rated in kW, but performance measured in kWh daily production), or comparing appliance efficiency ratings (often in kJ per cycle) to your electricity cost (cents per kWh).
Source: NIST SP 811, Table B.8
Frequently Asked Questions
Real-World Examples
A solar installer checking a battery spec: 3,600 kJ of storage capacity = 1 kWh. This battery could run a 1 kW heater for exactly 1 hour.
3600 kJ = 1 kWh
An energy auditor reviewing a heat pump spec with 36,000 kJ/day output = 10 kWh/day. At $0.15/kWh, the daily electricity cost is $1.50.
36000 kJ = 10 kWh
A consumer checking a portable power bank's capacity: 1,800 kJ (500 Wh, a common spec) = 0.5 kWh. Enough for ~4 hours of phone charging.
1800 kJ = 0.5 kWh
A building efficiency expert calculating overnight HVAC run. A 2 kWh setpoint (7,200 kJ) on a modern smart thermostat = roughly $0.30 in electricity for 8 hours of conditioning.
7200 kJ = 2 kWh