Therms to Kilojoules (thm to kJ)

1 therm equals 105,480.4 kilojoules exactly.

1 therm = 105,480.4 kilojoules

How to convert therms to kilojoules

To convert therms to kilojoules, multiply the number of therms by 105,480.4. This factor is exact. To go the other way, multiply kilojoules by 0.00000948043428 (rounded).

kilojoules = therms × 105,480.4

Example: 10 therms = 1,054,804 kilojoules.

The 'calorie' on food labels is really a kilocalorie. The thermochemical calorie (4.184 J) is used here unless marked IT.

About these units

Therm (thm)

US customaryTraditional unit (still used in some regions)

100,000 BTU (about 105.48 MJ). US natural gas bills are measured in therms.

Gas bills gave the therm its place in daily life. It is defined as 100,000 British thermal units, so its size depends on which BTU is meant. The figure used here, 105,480,400 joules or about 29.30 kWh, is the US therm, built on a BTU defined at 59 degrees Fahrenheit. The European Community version, based on the ISO BTU, is 105,506,000 joules, and the UK value is about 105,505,585 joules.

In the United States, natural gas is billed in therms or in CCF, hundreds of cubic feet. Pipeline companies adopted the decatherm, 10 therms or a million BTU, around 1972 to simplify invoicing, and roughly 1,000 cubic feet of gas holds about one decatherm.

Britain moved the other way. Regulations replaced therms with joules from 1999, retail customers now see kilowatt-hours, and only the wholesale market still quotes pence per therm. The EIA lists one therm as 100,000 Btu, and the Btu itself is the heat needed to warm a pound of water by one degree Fahrenheit.

1 therm = 105,480,400 joules (exactly).

Sources: Wikipedia: Therm; EIA: British thermal units (Btu); Wikipedia: British thermal unit

Kilojoule (kJ)

Metric (SI)Current unit

1,000 joules. Food labels in many countries give energy in kilojoules.

Most food labels around the world express energy in kilojoules, which is the calorie's long retirement in action. The calorie came out of heat measurement, and the 1948 CGPM resolution stated that the joule should be preferred as the unit of heat. Labels that still show kilocalories alongside kilojoules rely on the thermochemical calorie of exactly 4.184 joules, so one kilocalorie is about 4.184 kJ.

The kilojoule is a convenient size for a body's daily bookkeeping. A person at rest uses about 5,000 kJ, or roughly 1,200 kcal, per day, and the recommended intake for a moderately active woman is given as 2,000 food calories, which is about 8,400 kJ.

Smaller physical comparisons land in the same range. One watt-hour is 3.6 kJ, a British thermal unit is about 1.1 kJ, exploding a gram of TNT releases about 4.2 kJ, and an alkaline AA battery holds about 9 kJ.

1 kilojoule = 1,000 joules (exactly).

Sources: Wikipedia: Kilojoule; Wikipedia: Joule; Wikipedia: Orders of magnitude (energy)

Related conversions

See all energy units.