BTU to Joules (J) Converter
Instantly convert BTU to Joules (J) and Kilojoules (kJ). Our dual calculator also converts power from BTU/hr to Watts (J/s) for engineering and physics.
Energy Conversion (BTU ↔ J ↔ kJ)
Power Conversion (BTU/hr ↔ W ↔ kW)
How to Use This Converter
Enter any value in the energy group to instantly switch between BTU, Joules, and Kilojoules. The power group converts appliance ratings (BTU/hr) into Watts and Kilowatts. Use the Calculate button if you prefer a refresh on demand; typing also keeps the interface up to date.
Methodology
Conversions rely on published equivalencies. Energy conversions cross reference BTU, Joules, and Kilojoules through a shared Joule-based unit. Power conversions first normalize to Watts (Joules per second) and then express the same quantity as BTU per hour or kilowatts.
- Entering zero or leaving a field blank clears previous equivalents while keeping controls responsive.
- Precision follows seven significant digits to keep tracings stable across browsers.
- When both energy and power inputs are provided, the calculator keeps them independent so you can compare rows side-by-side.
Energy vs. Power
The first group handles total energy (BTU, Joules, Kilojoules). The second group focuses on power (BTU/hr, Watts, Kilowatts). Remember that energy measures the amount of heat, while power measures how fast that heat is delivered.
- Energy (BTU, Joule): A total amount of heat or work.
- Power (BTU/hr, Watt): The rate of energy flow (Watts are Joules per second).
This page bundles both calculators so you can switch between energy and power use cases without navigating elsewhere.
Conversion Quick Facts
Power: 1 BTU/hr = 0.293071 Watts = 0.000293071 Kilowatts
Common Conversion Chart
| BTU (Energy) | Joules (J) | BTU/hr (Power) | Watts (W) |
|---|---|---|---|
| 1 BTU | 1,055 J | 1 BTU/hr | 0.293 W |
| 100 BTU | 105,506 J | 1,000 BTU/hr | 293 W |
| 1,000 BTU | 1.055 MJ | 3,412 BTU/hr | 1,000 W (1 kW) |
| 10,000 BTU | 10.55 MJ | 10,000 BTU/hr | 2,931 W (2.93 kW) |
Frequently Asked Questions
What is the formula for BTU to Joules (J)?
The formula is: Joules = BTU × 1055.056.
How many Joules are in 1 BTU?
There are 1,055.056 Joules (or 1.055 kilojoules) in 1 British Thermal Unit (BTU).
What is the difference between BTU/hr and Joules/second (Watts)?
BTU/hr and Watts both measure power (the rate of energy flow). A Watt equals 1 Joule per second, so 1 BTU/hr = 0.293071 Watts.
How many Joules are in a kBTU?
1 kBTU equals 1,055,056 Joules because 1,000 BTU × 1,055.056 J/BTU = 1,055,056 J.
About the author
Ugo Candido builds scientific and financial calculators with transparent models so readers can verify how numbers are computed.
Contact: info@calcdomain.com
Editorial policy
CalcDomain articles are educational and reviewed for clarity and accuracy. We refuse paid placements that influence results, and every assumption is visible in the interface so you can reproduce the math.