# British thermal unit (IT) conversions

energy conversions » British thermal unit (IT) conversionsThe online converter calculator on this page allows you to select the energy measurement unit you want to convert to starting from British thermal units (IT) (BTU). To make a conversion starting from a unit of energy other than British thermal unit (IT), simply click on the "Reset" button.

## What is British thermal unit (IT)?

### Definition:

The British thermal unit (IT) is a unit of energy equal to 1,055.05585 joules (1 BTU = 1,055.05585 J), the SI derived unit of energy. It is also equal to 1.05505585 kilojoules (kJ), or 252.164401 calories (thermochemical) (cal), or 0.252164401 kilocalories (thermochemical) (kcal), or 0.5555556 Celsius heat units (IT) (CHU), or 0.29307107 watt hours (Wh) or 0.00029307107 kilowatt hours (kWh).

The British thermal unit is the energy required to increase the temperature of a pound of water by one degree Fahrenheit (or 0.556 degrees Celsius) at a constant pressure of one atmosphere.

The British thermal unit definition varies as follows:

- The British thermal unit (IT) (BTU) is equal to 1,055.05585262 joules (J)
- The British thermal unit (ISO) (BTU) is equal to 1,055.056 joules (J)
- The British thermal unit (thermochemical) (BTU) is equal to about 1,054.35026444 joules (J)
- The British thermal unit (mean) (BTU) is equal to about 1,055.87 joules (J)
- The British thermal unit (39 °F) (BTU) is equal to about 1,059.67 joules (J)
- The British thermal unit (59 °F) (BTU) is equal to 1,054.804 joules (J)
- The British thermal unit (60 °F) (BTU) is equal to about 1,054.68 joules (J)
- The British thermal unit (63 °F) (BTU) is equal to about 1,054.6 joules (J)

The most common BTU multiples are:

- One thousand British thermal units (MBTU, MBtu, e3BTU, BTUE3), equal to 1,000 BTU
- One million British thermal units (MMBTU, MMBtu, e6BTU, BTUE6), equal to 1,000,000 BTU
- One therm, equal to 100,000 BTU
- One quad (energy) (or quadrillion BTU), equal to 1015 BTU

The BTU is commonly used in the power generation, steam generation, heating and air conditioning industries. Usually, the BTU-IT is used in the European Union while the BTU-59 °F is used in the United States.

*Notes:*

(i) The SI is an abbreviation for the International System of Units

(ii) The IT is an abbreviation for the International [Steam] Table

(iii) The ISO is an abbreviation for the International Organization for Standardization

### Symbol:

BTU

### Plural:

British thermal units (IT)

Below you can find a comprehensive list with conversions from British thermal units (IT) to other (metric, imperial, or customary) energy measurement units.