Skip to main content

Convert British Thermal Units to Kilojoules

Instantly convert British Thermal Units (BTU) to Kilojoules (kJ) with our free online calculator.

Formula: BTU to kJmultiply by 1.05506

Reference Table

British Thermal Units (BTU)Kilojoules (kJ)
11.05506
55.2753
1010.5506
2526.3765
5052.753
100105.506

How to Convert British Thermal Units to Kilojoules

Formula

To convert British Thermal Units (BTU) to Kilojoules (kJ): multiply by 1.05506

Step-by-Step

  1. Start with your value in British Thermal Units (BTU).
  2. Multiply by 1.05506 to perform the conversion.
  3. The result is your value expressed in Kilojoules (kJ).

Conversion Factor

1 BTU = 1.05506 kJ

Reverse Factor

1 kJ = 0.947813 BTU

Worked Example

Convert 25 British Thermal Units to Kilojoules: 25 BTU = 26.3765 kJ

About British Thermal Unit (BTU)

An imperial unit of heat energy, defined as the amount of heat required to raise one pound of water by 1°F (about 1,055 joules). BTUs are the dominant unit in US HVAC and heating/cooling: air conditioner capacity (a 12,000 BTU/h unit is a "1-ton AC"), gas furnace output, and natural gas heating content. "MMBTU" (million BTU) is the US energy wholesale unit for natural gas and industrial fuel contracts.

About Kilojoule (kJ)

A metric unit of energy equal to 1,000 joules. Kilojoules are the standard unit for food energy outside the United States — Australia, New Zealand, and the European Union all display kJ on nutrition panels. A Big Mac is roughly 2,220 kJ; an adult daily energy intake is typically 8,000–10,500 kJ. The kJ is also the natural engineering unit for mechanical work, battery capacity, and small-scale thermodynamic calculations.

Quick Facts

  • 1 British Thermal Unit equals 1.05506 Kilojoules
  • 1 Kilojoule equals 0.947813 British Thermal Units
  • British Thermal Unit is a unit of energy
  • Kilojoule is a unit of energy
  • This conversion is commonly used in nutrition, electrical billing, physics, and mechanical engineering
  • The British Thermal Unit belongs to the imperial system
  • The Kilojoule belongs to the metric system

Common British Thermal Unit to Kilojoule Conversions

British Thermal Units (BTU)Kilojoules (kJ)
0.010.0105506
0.10.105506
0.250.263765
0.50.52753
11.05506
22.11012
33.16518
55.2753
1010.5506
1515.8259
2021.1012
2526.3765
5052.753
7579.1295
100105.506
250263.765
500527.53
10001055.06
50005275.3
1000010550.6

Understanding British Thermal Units

The British Thermal Unit (symbol: BTU) is a unit of energy. An imperial unit of heat energy, defined as the amount of heat required to raise one pound of water by 1°F (about 1,055 joules). BTUs are the dominant unit in US HVAC and heating/cooling: air conditioner capacity (a 12,000 BTU/h unit is a "1-ton AC"), gas furnace output, and natural gas heating content. "MMBTU" (million BTU) is the US energy wholesale unit for natural gas and industrial fuel contracts.

It belongs to the imperial measurement system.

British Thermal Units are commonly used in nutrition, electrical billing, physics, and mechanical engineering.

Understanding Kilojoules

The Kilojoule (symbol: kJ) is a unit of energy. A metric unit of energy equal to 1,000 joules. Kilojoules are the standard unit for food energy outside the United States — Australia, New Zealand, and the European Union all display kJ on nutrition panels. A Big Mac is roughly 2,220 kJ; an adult daily energy intake is typically 8,000–10,500 kJ. The kJ is also the natural engineering unit for mechanical work, battery capacity, and small-scale thermodynamic calculations.

It belongs to the metric measurement system.

Kilojoules are commonly used in nutrition, electrical billing, physics, and mechanical engineering.

Why Convert British Thermal Units to Kilojoules?

Converting energy between British Thermal Units and Kilojoules is common in physics, nutrition, and engineering. Electricity bills use kilowatt-hours, food labels list calories or kilojoules, and mechanical engineers work with joules and BTUs. Reliable conversion helps professionals and consumers compare energy values across different contexts.

Frequently Asked Questions

How do I convert British Thermal Units to Kilojoules?

An imperial unit of heat energy, defined as the amount of heat required to raise one pound of water by 1°F (about 1,055 joules). To convert British Thermal Units to Kilojoules, multiply by 1.05506. For example, 25 BTU equals 26.3765 kJ.

How many Kilojoules are in 1 British Thermal Unit?

There are 1.05506 Kilojoules in 1 British Thermal Unit.

How many British Thermal Units are in 1 Kilojoule?

There are 0.947813 British Thermal Units in 1 Kilojoule.

What is the formula for British Thermal Unit to Kilojoule conversion?

The formula is: multiply by 1.05506. This means 1 BTU = 1.05506 kJ.

Is a British Thermal Unit bigger than a Kilojoule?

No. One British Thermal Unit is smaller than one Kilojoule because 1 BTU equals 1.05506 kJ, which is greater than 1.

When do you need to convert between British Thermal Units and Kilojoules?

A metric unit of energy equal to 1,000 joules. British Thermal Unit and Kilojoule are both energy units, so conversion comes up whenever one source of information uses one unit and another uses the other — a classic cross-reference challenge in engineering, trade, travel, and everyday life.

More Energy Conversions

Related Tools