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Convert Kilojoules to British thermal units

1 kilojoule is 0.947817 BTU. One kilojoule is exactly 0.947817120313 British thermal units.

One kilojoule is 0.94781712 British thermal units. To convert kilojoules to British thermal units, multiply by 0.94781712; to go the other way, divide by 0.94781712 or multiply by 1.0550559. The factor is exact rather than rounded: it follows from NIST Special Publication 811. A thousand joules.

Factor checked against the defining standard · How we check

British thermal units
0.947817 BTU
Kilojoules × 0.94781712
value * 0.9478171203130.948 BTU

1 kilojoule in every energy unit

UnitValueExact factor
joules1,000 J× 1,000
kilojoules (as entered)1 kJ
calories239.0057361 cal× 239.005736138
kilocalories0.2390057361 kcal× 0.239005736138
watt-hours0.2777777778 Wh× 0.277777777778
kilowatt-hours0.0002777777778 kWh× 0.000277777777778
British thermal units0.9478171203 BTU× 0.947817120313
foot-pounds737.5621493 ft·lbf× 737.562149277

Factors are entered by hand from NIST Special Publication 811 rather than derived from a units library, so the ones that terminate are exact rather than rounded.

How do you convert kilojoules to British thermal units?

  1. 1.Take the measurement in kilojoules.
  2. 2.Multiply by 0.94781712 — that is how many British thermal units fit in one kilojoule.
  3. 3.To go back the other way, divide by 0.94781712, or multiply by 1.0550559.

Worked example: 25 kilojoules to British thermal units

Formula
kJ × 0.94781712 = BTU
Arithmetic
25 × 0.94781712 = 23.695428 BTU
Answer
25 kJ = 23.695428 BTU

The factor is rounded for display; the figure above is computed from the full value.

Kilojoules to British thermal units conversion table

KilojoulesBritish thermal units
1 kJ0.947817 BTU
2 kJ1.895634 BTU
3 kJ2.843451 BTU
4 kJ3.791268 BTU
5 kJ4.739086 BTU
6 kJ5.686903 BTU
7 kJ6.63472 BTU
8 kJ7.582537 BTU
9 kJ8.530354 BTU
10 kJ9.478171 BTU
12 kJ11.373805 BTU
15 kJ14.217257 BTU
20 kJ18.956342 BTU
25 kJ23.695428 BTU
50 kJ47.390856 BTU
100 kJ94.781712 BTU
200 kJ189.563424 BTU
300 kJ284.345136 BTU
500 kJ473.90856 BTU
1000 kJ947.81712 BTU
2000 kJ1,895.634241 BTU
5000 kJ4,739.085602 BTU
10000 kJ9,478.171203 BTU

What is a kilojoule?

A thousand joules. Food energy outside the US is labelled here, alongside or instead of calories.

What is a British thermal unit?

The international-table BTU, fixed at exactly 1055.05585262 joules. Roughly the heat needed to raise a pound of water by one degree Fahrenheit, which is where it came from.

How many British thermal units are in a kilojoule?

One kilojoule is 0.94781712 British thermal units. Going the other way, one British thermal unit is 1.0550559 kilojoules. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.

Every energy unit here

UnitSymbolOne of these is
JoulesJthe base unit
KilojouleskJ1000 joule
Caloriescal4.184 joule
Kilocalorieskcal4184 joule
Watt-hoursWh3600 joule
Kilowatt-hourskWh3600000 joule
British thermal unitsBTU1055.0559 joule
Foot-poundsft·lbf1.3558179 joule

Source: NIST Special Publication 811 — the thermochemical calorie is exactly 4.184 J

Questions people actually ask

How many British thermal units are in a kilojoule?
0.94781712. The international-table BTU, fixed at exactly 1055.05585262 joules. Roughly the heat needed to raise a pound of water by one degree Fahrenheit, which is where it came from.
How do I convert British thermal units back to kilojoules?
Divide by 0.94781712, or multiply by 1.0550559 — they are the same operation.

Other energy conversions

British thermal units to kilojoules — the same conversion the other way.

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