BTU (IT) to Joules (J) Converter
Enter a value to instantly convert between energy units.
1 BTU (IT) = 1055.0559 Joule
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
J = BTU × 1055.056One BTU (IT) equals exactly 1055.056 joules — the energy to raise one pound of water by one degree Fahrenheit. BTU is the standard unit for US heating and cooling equipment, water heaters, and industrial furnaces. Converting to joules is needed when working with metric documentation or international standards. For the reverse conversion, see [joules to BTU](/energy/joules-to-btu/).
Source: NIST SP 811, Table B.8
Frequently Asked Questions
Real-World Examples
An energy auditor converting 1 BTU from a furnace specification to joules for the international report — 1055 J.
1 BTU = 1055.06 J
A boiler rated at 50,000 BTU/hour produces 52,753,000 J/hour — 52.75 MJ/h for the metric spec.
50000 BTU = 52753000 J
A heating contractor calculating 100 BTU from a space heater reports 105,506 J in the quote.
100 BTU = 105506 J
An HVAC technician verifying 10 BTU of heat addition equals 10,550 J for the heat pump calculation.
10 BTU = 10550.56 J