What is therm (US)?
A US therm is a unit of energy equal to 100,000 BTU. It is used by gas utility companies in the United States as the standard billing unit for natural gas consumption.
Real-world uses
The therm is used in the United States and United Kingdom for natural gas billing. One therm equals 100,000 BTU (approximately 29.3 kWh). Residential gas bills in the US often list consumption in therms. It is also used in industrial gas metering and procurement contracts.
History
The therm was introduced as a practical unit for natural gas billing in the early 20th century, when gas supply companies needed a convenient large-scale energy unit for residential and commercial customers. It consolidated prior inconsistent measurement practices in the gas industry.
Common mistakes
Confusing the therm with the BTU—1 therm = 100,000 BTU. Also, the US therm and the UK therm differ slightly (the UK therm is based on 105.5 MJ, while the US therm is exactly 100,000 BTU ≈ 105.48 MJ). Not to be confused with the thermie (a metric unit of heat).
What is kilojoule?
A kilojoule is a unit of energy equal to 1,000 joules. It is commonly used in nutrition to express the energy content of food, as well as in thermodynamics and mechanical engineering.
Real-world uses
Kilojoules are the standard energy unit for food nutrition labelling in Australia, New Zealand, and parts of Europe (alongside kilocalories). A typical adult daily intake is about 8,700 kJ. They are also used in chemistry for reaction enthalpies and combustion energies.
History
The kilojoule became important in nutrition labelling as countries adopted SI-based energy reporting. Australia was among the first to mandate kJ on food labels in the 1970s. The EU requires both kJ and kcal on nutrition labels.
Common mistakes
Confusing kilojoules with kilocalories—1 kcal = 4.184 kJ. Food labels showing "2000 kJ" are about 478 kcal, not 2000 kcal. Also, some people incorrectly assume kJ and kW are the same thing; one is energy, the other is power.
When is this conversion used?
Converting between therm (US) and kilojoule is common when working across metric and imperial systems, such as international trade, travel between countries with different measurement standards, or following instructions from a different region. Nutritional information is labelled in kilocalories in some countries and kilojoules in others, making this conversion important for dietary planning and food science.
Worked examples
1 therm (US) = 105,506 kilojoule
1 kilojoule = 1,000 joule
How to convert therm (US) to kilojoule
To convert therm (US) to kilojoule, multiply the value by 105,506.
To convert kilojoule back to therm (US), multiply by 0.00000948.
Measurement standards
The joule is the SI derived unit of energy, defined as one kilogram-metre-squared per second-squared (kg·m²/s²). The kilowatt-hour, equal to exactly 3.6 megajoules, is accepted for use with the SI by the BIPM for practical electricity metering.
Did you know?
A single bolt of lightning releases roughly 1 to 5 gigajoules of energy, yet only a small fraction reaches the ground as electrical current. Most of the energy dissipates as light, heat, and the thunder shockwave.
Quick reference: therm (US) to kilojoule
| therm (US) | kilojoule |
|---|---|
| 0.1 | 10,550.6 |
| 0.5 | 52,753 |
| 1 | 105,506 |
| 2 | 211,012 |
| 5 | 527,530 |
| 10 | 1,055,060 |
| 25 | 2,637,650 |
| 50 | 5,275,300 |
| 100 | 10,550,600 |
| 250 | 26,376,500 |
| 500 | 52,753,000 |
| 1,000 | 105,506,000 |
Common values
| therm (US) | kilojoule | |
|---|---|---|
| A food calorie (1 kcal) | 0.00003966 therm (US) | 4.184 kilojoule |
| A AA battery | 0.00008872 therm (US) | 9.36 kilojoule |
| Boiling a kettle | 0.00398082 therm (US) | 420 kilojoule |
| Daily human diet (2000 kcal) | 0.07931302 therm (US) | 8,368 kilojoule |
| 1 gallon of gasoline | 1.24883893 therm (US) | 131,760 kilojoule |
Available Energy units
More therm (US) conversions
- Convert therm (US) to joule
- Convert therm (US) to kilojoule
- Convert therm (US) to kilowatt hour
- Convert therm (US) to calorie (thermochemical)
- Convert therm (US) to kilocalorie (dietary)
- Convert therm (US) to watt hour
- Convert therm (US) to megajoule
- Convert therm (US) to electronvolt
- Convert therm (US) to British thermal unit
Assumption: calorie means thermochemical calorie, and therm means US therm.