Kilojoules (kJ) to BTU (IT) Converter
Enter a value to instantly convert between energy units.
1 Kilojoule = 0.9478 BTU (IT)
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
BTU = kJ × 0.9478171One kilojoule equals 0.948 BTU (British Thermal Units). Kilojoules are the SI standard for energy; BTU is the US/imperial thermal unit. Converting kJ to BTU is essential when comparing international HVAC equipment (rated in kJ) with US building codes, furnaces, and air conditioners (rated in BTU) — for example, a metric air conditioner rated 10 kJ/h must be compared to US equipment in BTU/h.
Source: NIST SP 811, Table B.8
Frequently Asked Questions
Real-World Examples
Definition: 1.055056 kJ = exactly 1 BTU (IT) — conversion constant.
1.055056 kJ = 1 BTU
A European heat pump rated 10 kW input = 10,000 kJ/s output = 9,478 BTU/s for US specification sheet.
10000 kJ = 9478.17 BTU
A metric air conditioner rated 12.66 kJ/h = 12,000 BTU/h (1-ton unit) — standard for bedroom cooling.
12.66 kJ = 12 BTU
A hydronic heater produces 100 kJ/h = 94.78 BTU/h — converted for the international building code report.
100 kJ = 94.78 BTU