Energy products are measured in physical units by their mass, volume, and energy content. The measurement units that are specific to an energy product and are employed at the point of measurement of the energy flow are often referred to as “original” or “natural” units. Crude oil, for example, is generally measured by its volume. For natural gas, densities change with pressures and temperatures, and therefore, it is important to use standardized volumes.

This guide identifies commonly used units of measurements for various product types, and their abbreviations. As much of the work under this trilateral effort requires comparing, and presenting energy information in a consistent manner, conversion factors to be used when moving between imperial and metric systems of measurement are presented. When required factors are not identified below, we recommend using those provided by the International Energy Agency and/or the International Recommendations for Energy Statistics (IRES)^{Footnote 1}.

## Prefixes and Equivalents

Prefix |
Equivalent |
|||
---|---|---|---|---|

SI/Metric |
Imperial |
|||

k | kilo | M | thousand | 10^{3} |

M | mega | MM | million | 10^{6} |

G | giga | B | billion | 10^{9} |

T | tera | T | trillion | 10^{12} |

P | peta | - | quadrillion | 10^{15} |

## Common Units

Crude oil, natural gas liquids, and petroleum products

Abbreviation |
Description |
---|---|

L | Litres |

gal | Gallons |

bbl | Barrels |

b/d | barrels per day |

Mb | thousand barrels |

Mb/d | thousand barrels per day |

MMb | million barrels |

MMb/d | million barrels per day |

m^{3} |
cubic metre |

m^{3}/d |
cubic metres per day |

## Natural gas

Abbreviation |
Description |
---|---|

cf | cubic feet |

Mcf | thousand cubic feet |

Mcf/d | thousand cubic feet per day |

MMcf | million cubic feet |

MMcf/d | million cubic feet per day |

Bcf | billion cubic feet |

Bcf/d | billion cubic feet per day |

Tcf | trillion cubic feet |

m^{3} |
cubic metre |

m^{3}/d |
cubic metres per day |

Btu | British thermal units |

MMBtu | million British thermal units |

Btu/cf | British thermal units per cubic foot |

MTPA | million tonnes per annum (of LNG) |

kPa | kilo pascal |

psi | pound per square inch |

psia / kPaa | atmospheric pressure |

## Electricity

Abbreviation |
Description |
---|---|

V | Volt |

kV | Kilovolt |

MW | Megawatt |

kWh | kilowatt hour |

MWh | megawatt hour |

GWh | gigawatt hour |

TWh | terawatt hour |

## Common conversions

### Conversion factors for volume

#### Liquids

Input unit |
Output unit |
Multiply by |
---|---|---|

barrels (bbl) | cubic metres (m^{3}) |
0.158987295 |

cubic metres (m^{3}) |
barrels (bbl) | 6.28981077 |

barrels (bbl) | litres (l) | 158.987295 |

litres (l) | barrels (b) | 0.00628981077 |

barrels (bbl) | cubic feet (cf) | 5.61458333 |

cubic feet (cf) | barrels (bbl) | 0.178107607 |

litres (l) | cubic metres (m^{3}) |
0.00100000000 |

cubic metres (m^{3}) |
litres (l) | 1000.00000 |

litres (l) | gallons (US gal) | 0.264172052 |

gallons (US gal) | litres (l) | 3.78541178 |

#### Gases

The two common standardized volumes used internationally and for the purpose of this trilateral effort are:

cubic feet measured at 60°F (15.6°C) and 14.73 psia, and

cubic metres measured at 15°C and 101.325 kPaa.

Input unit |
Output unit |
Multiply by |
---|---|---|

cubic metres (m3) | cubic feet (cf) | 35.3146667 |

cubic feet (cf) | cubic metres (m^{3}) |
0.0283168466 |

standard cubic metre (Sm3) | normal cubic metre (Nm^{3}) |
0.948000000 |

normal cubic metre (Nm^{3}) |
standard cubic metre (Sm^{3}) |
1.05500000 |

Note: Sm^{3} measured at 15°C and 101.325 kPa,
Nm^{3} measured at 0°C and 101.325 kPa.

#### Liquefied natural gas (LNG)

Input unit |
Output unit |
Multiply by |
---|---|---|

cubic metres (m^{3}) LNG |
cubic metres (m^{3}) natural gas |
615.000000 |

cubic metres (m^{3}) natural gas |
cubic metres (m^{3}) LNG |
0.001626016 |

cubic metres (m^{3}) LNG |
cubic feet (cf) natural gas | 21,718.5200 |

cubic feet (cf) natural gas | cubic metres (m^{3}) LNG |
0.000046044 |

million tonnes LNG | billion cubic feet (bcf) natural gas | 48.0279467 |

billion cubic feet (bcf) natural gas | million tonnes LNG | 0.0208212107 |

million tonnes LNG per year (MTPA) | billion cubic feet natural gas per day (Bcf/d) | 0.131584156 |

billion cubic feet natural gas per day (Bcf/d) | Million tonnes LNG per year (MTPA) | 7.59974192 |

Note: LNG conversion factors can vary with reference conditions and feed gas composition.

#### Conversion factors for pressure

Input unit |
Output unit |
Multiply by |
---|---|---|

kilopascal (kPa) | pounds per square inch (psi) | 0.145037738 |

pounds per square inch (psi) | kilopascal (kPa) | 6.89475729 |

#### Conversion factors for energy

Input unit |
Output unit |
Multiply by |
---|---|---|

British thermal unit (Btu) | calories (cal) | 251.995761 |

calories (cal) | British thermal unit (Btu) | 0.00396832072 |

British thermal unit (Btu) | joules (J) | 1055.05585 |

joules (J) | British thermal unit (Btu) | 0.000947817120 |

joules (J) | calories (cal) | 0.238845897 |

calories (cal) | joules (J) | 4.186800001 |

joules (J) | watt-hour (Wh) | 0.000277777778 |

watt-hour (Wh) | joules (J) | 3600.00000 |

- Date Modified: