BTU (th) to Kilojoule Converter

Energy Converter

27 units available

Decimals:

From

To

1.05435

1 BTU = 1.05435 kJ

Formula:

kJ = BTU × 1.05435

With your value: 1 BTU = 1.05435 kJ

How big is that?

Everyday references on a logarithmic scale, all expressed in btu (th) so you can sanity-check the result.

Heartbeat (1/1.1e+3 your value)0.000948 BTU

Your value1.00 BTU

AA battery charge (9.5× your value)9.48 BTU

Slice of bread (2.7e+2× your value)266 BTU

Daily food intake (8.0e+3× your value)7.97e+3 BTU

Litre of petrol (3.2e+4× your value)3.24e+4 BTU

Other BTU (th) to Kilojoule conversions

2 BTU to kJ 3 BTU to kJ 4 BTU to kJ 5 BTU to kJ 6 BTU to kJ 7 BTU to kJ 8 BTU to kJ

BTU (th) to Kilojoule Conversion Table

BTU (th) (BTU)	Kilojoule (kJ)
0.5	0.527175
1	1.05435
2	2.1087
5	5.27175
10	10.5435
15	15.81525
20	21.087
25	26.35875
50	52.7175
100	105.435
250	263.5875
500	527.175
1000	1,054.35

Kilojoule to BTU (th) Conversion Table

Kilojoule (kJ)	BTU (th) (BTU)
0.5	0.474226
1	0.948452
2	1.896903
5	4.742258
10	9.484517
15	14.226775
20	18.969033
25	23.711291
50	47.422583
100	94.845165
250	237.112913
500	474.225826
1000	948.451653

Where these values come from

Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.

BTU (th) (BTU)

Energy

Exact conversion

The International Table BTU is exactly 1055.055 852 62 J.

Thermochemical and 39 °F BTU definitions differ by up to 0.2 %.

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

Kilojoule (kJ)

Energy

Exact conversion

Derived from the joule (1 J = 1 kg·m²/s²). Thermochemical and IT calories, BTU and kWh are exact defined multiples.

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

How to Convert BTU (th) to Kilojoule

To convert from BTU (th) (BTU) to Kilojoule (kJ), multiply the value by 1.05435.

Formula: kJ = BTU × 1.05435

Reverse: BTU = kJ × 0.9484516527

Step-by-Step Example

Start with your value in BTU (th). For example: 5 BTU
Multiply by the conversion factor: 5 x 1.05435
The result is: 5.27175 kJ

About BTU (th)

The btu (th) (BTU) is a unit of energy and work. One btu (th) equals 1054.35 joules. UnitConvertLab converts it against every other energy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: energy calculations, engineering and science, education.

About Kilojoule

The kilojoule (kJ) is a unit of energy and work. One kilojoule equals 1000 joules. UnitConvertLab converts it against every other energy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: energy calculations, engineering and science, education.

Frequently Asked Questions

How many Kilojoule are in 1 BTU (th)?

There are exactly 1.05435 Kilojoule in 1 BTU (th). This means the conversion factor from BTU (th) to Kilojoule is 1.05435.

What is the formula to convert BTU (th) to Kilojoule?

The formula to convert BTU (th) to Kilojoule is: kJ = BTU × 1.05435. For example, to convert 10 BTU (th) to Kilojoule, you would multiply 10 by 1.05435.

What is a BTU (th)?